While Naples may claim the coveted title as the birthplace of modern-day pizza (when tomato was added back in the 18th century), it's surprisingly Norway that devours more pizza per capita than any other country in the world. But with the global pizza market valued at roughly US$160 billion and more than 30 billion pizzas consumed worldwide per year, it's no surprise that dozens of countries claim 'za as their unofficial national dish.

And Shanghai has no shortage of the holy trinity in which dough, sauce and cheese meet and melt in perfect harmony – from bubbled up, charred-edges on Neapolitan pies to New York slices ideal for rolling like a taco; from hefty interspersed layers of sauce, cheese and meat stacked 15cm-high as Chicago deep dish to bulgy foccacia-esque servings of Detroit pizza.

There's tavern style, white pizza, Sicilian squares, baked and fried calzones, and stuffed crust. Further afield there's Turkish pide, Georgian khachapuri, Meixcan tlayuda, Middle Eastern lahmacun, and German flammkuchen.

Pizza is up there as one of the most unifying and polarizing of iconic worldly foods, and the interminable debate over Shanghai's best pizza is an apples-to-oranges situation – one we can't bring ourselves to take sides in.

So, instead, we've put together a Shanghai global pizza tour, traversing the United States to Europe, the Middle East to the Mediterranean, all available in our own backyard. While it would be an insurmountable feat to visit every pizza-serving venue across town, we've instead selected a handful of worldly pizza styles and listed our favorite place(s) within Shanghai's borders to try.

Buckle up, Shanghai, it's gonna be a cheesy ride.

California Style Pizza – O'Mills & Sub Standard

The Cali-style pizza is all about the unconventional, gourmet garnishes atop a thinner, high-hydration, hand-tossed dough. An amalgamation of a New York-style pizza and a Neapolitan pizza, the Cali pizza is credited to chef Ed LaDou (dubbed 'The Prince of Pizza') and Chez Panisse in Berkeley, California, in the early 1980s, which was later further popularized by the Wolfgang Puck chain.

Generally deemed to be "lighter and healthier" to fit that Cali beach lifestyle, the crust tends to be made with extra virgin olive oil, while toppings run the gamut from BBQ chicken, goat cheese and sundried tomatoes to smoked salmon, crème fraiche, dill and salmon roe.

At O'Mills, they are dishing out pure Cali-style pizzas made with their homemade sourdough starter, one that ferments for at least 72 hours, ensuring optimal digestibility. Think epicurean flavor profiles: black truffle with bacon and poached egg, homemade Wagyu beef sausage and asparagus, prosciutto and burrata, and even grilled eel with white sesame, seaweed and chives.

More of a North Beach Cali-style vibe, Sub Standard does unpretentious ingredients on a 12", 38-72 hour aged and cold fermented dough that translates to some pretty standout Cali-style crust. Salty and warm, the corners crisp while the center remains soft – so you can fill up on toppings more than just carbs.

If you go...

Sub Standard, 230 Wanhangdu Rd, by Xinzha Rd

O'Mills, S1-02&03,1/F, South Bldg, Jing'an Kerry Center, 1515 Nanjing Rd W., by Anyi Road

Calzone – Bottega

Naples doubles down on pizza in all shapes, forms, and cooking techniques, of which there are an astounding array on every street corner.

Case in point, the calzone – a folded pizza that first made an appearance in the 18th century in Naples. Equal parts convenient (for those on the go-go-go), compact and crushable, this envelope of ooey-gooey cheesy joy sees all the customary pizza toppings stuffed inside (or partially atop) it.

Bottega scores another win for Shanghai's best calzone, available fritto – aka fried – or baked, replete with gobs of melted mozz, tangy San Marzano tomatoes and a choice of meat.

This puffed-up pocket of gluttony arrives tableside roughly the size of a newborn baby in length and weight, stuffed to the gills with – well – all the good stuff. Plan ahead for this one, you're most definitely going to need a co-pilot.

If you go...

Bottega, 1/F, 101B, K.WAH CENTRE, 108 Xiangyang Rd N., by Huaihai Rd M.

Bottega Jing'an, 457 Shaanxi Rd N., by Beijing Rd W.

Chicago Deep Dish Style Pizza – Cages

With a history dating back to 1943 at the Chicago institution that is Uno Pizzeria, Chicago-style deep dish is the heftiest pie on the list. Cooked in a deep, circular pan so the buttery crust stacks at least a few finger widths high, the pizza is layered in scrummy stratum – like a lasagna sans the pasta sheets – with tangy tomato sauce, gobs of cheese, and meat and/or veggie toppings. A single pizza can easily feed an entire family as your average eater can't make it past just one behemoth slice.

Shanghai's most successful all-in-one live sports bar, Cages, serves up six varieties of Chicago-style deep dish for just one day only every month (the third Sunday of every month), for pre-order reservations. Why is all the pre-planning necessary, you ask? Well, the average pie clocks in at a whopping three kilos – a Frankenfeast of cheesy, meaty goodness.

Regardless of your pizza topping choice (every month there's cheese, vegetarian, meat lover, chicken parmesan, pepperoni and one bonus monthly flavor), an avalanche of cheese ensues with 300 grams of smoked provolone, 700 grams of mozzarella, and a liberal top-coating of Parmesan for over a kilo of pure cheese heaven.

On top of all that cheese, the Pepperoni Madness Pizza sees 400 grams of spicy pepperoni, and the Meat Lovers Pizza boasts 800 grams of pepperoni, sausage and meatball.

The crust itself puts the "pie" in "pizza pie" with a 15 percent butter-to-flour ratio – if you're wondering why it tastes so rich, well, it should with all that butter. Proofing is non-essential as its more akin to a pie crust than the conventional bread crust. And even the sauce is reduced down more than your average 'za to avoid excess moisture for maintaining that crumbly crust texture.

The next Chicago Deep Dish Day at Cages is set for June 15th, and the flavor of the month is Truffle Mushroom. To reserve now, call 021-5299-5273.

If you go...

Cages Jing'an, 3/F, Jing'an Sports Center, 428 Jiangning Rd, by Wuding Rd

Detroit Style Pizza – Homeslice

Using steel pans from the United States' automobile capital, aka Motor City, Detroit-style pizza is identifiable by its signature rectangular shape and crackly corner pieces, influenced by square Sicilian-style pizza. The double-stretched, high-hydration (70 percent or more) dough is at once fluffy yet thick, like a porous focaccia, with lacy, cheesy edges that sear to a satisfying frico-style cheese crust.

Homeslice claims the title as the home of Shanghai's tastiest Detroit pizza, available both in-store and for delivery once a month, by reservation only.

"Hydration is critical for dough structure, as the conversion of the water into steam as it heats creates air bubbles," says Homeslice owner Nat Alexander. "Fermentation in dough is another critical factor, which develops both structure and flavor. Longer, lower temperature fermentations mean that the yeasts do more work creating flavor, rather than just adding air to the dough."

The baking process is a true labor of love, a multi-step cooking method including: a pre-bake tempering of the dough, shaping it in the pan and painting it with extra virgin oil; par-baking it a third of the way through, then adding cheese. (Wisconsin brick cheese is the preferred Detroit choice, but in Shanghai, where niche imports are hard to come by, a blend of mozzarella and cheddar does the trick). Next, there's baking the cheese-smothered bread for another third of the way through; then, finally adding other toppings for the final third of baking time. Heated sauce is added after baking, in stripes or dabs. You follow? If not, leave it to the pros.

From start to finish, the whole baking process takes 30 minutes.

Diners can select topping preferences at the time of booking, choosing amongst cheese, pepperoni, spicy sausage, or one rotating monthly flavor like buffalo chicken, burrata or Mexican.

To learn when the next Detroit Pizza Day is and to reserve your pie, message WeChat ID: Pizzaperfect.

If you go...

Homeslice, Unit 103, Bldg 3, 358 Kangding Rd, by Shaanxi Rd N., 康定路358号3幢103室

Khachapuri – Borsh & Kompot

A leavened and baked Georgian cheese-filled bread, khachapuri, is molded into an oval shape, pinched at the top and bottom, but left open in the center so the cheese, runny egg, and fillings can brown.

Found in both restaurants and at street stalls, pillowy khachapuri are such a signature dish of the Georgian nation that February 27 has been named National Khachapuri Day by the Gastronomic Association of Georgia, and the "khachapuri index" developed by the International School of Economics at Tbilisi State University is used to measure inflation across different Georgian cities.

Across Georgia, there are numerous varieties of khachapuri, with most variance occurring in the type of cheese used and filling. So much more than a time-honored food, khachapuri is truly a way of life in Georgia, with origins traced back to the 12th century.

At Russian/Georgian hangout, Borsh & Kompot, the team is cooking khachapuri on the daily, along with other nostalgic Slavic, home-style comfort eats. Using a textbook blend of all-purpose flour, milk, eggs, butter, and salt, the dough is then proofed for a few hours, depending on air temperature.

As Georgians most routinely combine two types of cheese for the khachapuri topping – a salty imeretian cheese (similar to feta) and a stretchy sulguni cheese (akin to mozzarella) – the team at Borsh & Kompot is emulating those cheese styles via artisan feta and and mozzarella, plus the addition of a cracked raw egg on top.

The 150 grams of cheese is swirled with the egg à la minute, with the khachapuri's rounded shape acting as a bowl. The heat of the melted cheese softly cooks the yolk, causing a gooey molten mass of dairy, the khachapuri crust serving as the ideal scooping vessel.

If you go...

Borsh & Kompot, 1411 Yuyuan Rd, by Changning Rd, 愚园路1411号, 近长宁路.

Manoushe/Lahmacun - Eli Falafel & Garlic

Originating in the Middle East (predominantly Turkey, Lebanon, Armenia, and Syria), lahmacun (also known as lahmajun, lahmajo, or lahm bi ajeen) is a flatbread of sorts that falls under the broader category of manakish (or manoushe), often referred to as Lebanese pizza.

Unlike most pizza styles, lahmacun and manoushe are not prepared with cheese, but rather with a minced meat spread, minced vegetables, and/or herbs and aromatics (onions, garlic, tomatoes, red peppers, parsley), and za'atar spice blend.

These flatbreads have been documented around the Middle East for thousands of years, roasted on metal frying pans – called tava – or cooked in tandoori ovens.

Lebanese-owned Eli Falafel is Shanghai's must-visit destination for all things falafel, shawarma, and kebabs. In addition to fusion style pizzas – a New York crust base with cheese and Middle Eastern toppings such as sujuck (a fermented spicy beef sausage from Middle Eastern and Balkan cuisine) – there's also traditional "Lebanese pizzas, finished with za'atar (dried thyme, sumac and toasted sesame seeds); lahme bi ajeen (minced meat, diced tomatoes, onions and a proprietary spice blend); falafel and vegetables; chicken or beef shawarma with fries, pickles, arugula, tomatoes, herbs and tahini; and many more Middle Eastern flavor-forward combinations.

And at Garlic, the lahmacun is uber-traditional, a spread of minced beef tenderloin, fatty minced lamb, tomato paste and onion across a half centimeter-thick oval of 30-minute proofed dough. The lahmacun is baked in a domed wood-fire oven for just 2-4 minutes, ensuring a cracker-like bottom with scorched edges.

If you go...

Eli Falafel Shanghai Center, Suite 111, 1/F, 1376 Nanjing Rd W., by Xikang Rd 地址 南京西路1376号上海商城1楼, 近西康路.

Garlic, 698 Yongjia Rd, by Anting Rd,永嘉路698号, 近安亭路.

New York Style Pizza – Homeslice

One of the world's most distinguished and popular pizza styles, the New York pizza is America's descendent version of the OG Neapolitan margherita. Created by Italian immigrants in New York in the early 1900s, Lombardi's is recognized as the birthplace of the famous New York slice.

Typically a thin crust, foldable triangular slice topped with tomato sauce, melted mozz, and any variety of add-ons under the sun – from pepperoni to sausage, from mushroom and spinach to pineapple and Canadian bacon – the original "secret ingredient" is actually New York's mineral-rich water that imbues the dough with a unique texture found only within the Big Apple's city limits.

Homeslice also claims the title as Shanghai's top-ordered New York-style pizza, with a dough that is characterized by several key features: lower temperature deck oven with predominantly bottom heat at (280-380-degrees Celsius), high gluten flour, and a hydration rate between 55-60 percent.

Homeslice uses a natural starter, as well as small amounts of yeast, and ferments the dough for a minimum of 48 hours at low temperature. Using a hydration level slightly higher than the average New York pizza, coupled with a shorter bake time of 6-7 minutes, Homeslice gets its signature "New York-style crust" still, but one that is more aerated.

Each season sees the launch of multiple special pies, and since opening in 2017, more than 110 pizza varieties have been served – from supa dupa cheese to zhajiang pizza, from chicken fajita to thirteen spices crayfish – and literally dozens more.

If you go...

Homeslice, Unit 103, Bldg 3, 358 Kangding Rd, by Shaanxi Rd N., 康定路358号3幢103室.

Naples – Bottega

The definition of Naples-style pizza is protected and regulated by the Associazione Verace Pizza Napoletana. Considered more than food – Neapolitan pizza represents a lifestyle and a tradition, as is evidenced by the fact that it's considered one of the nine foods on UNESCO's Intangible Cultural Heritage List.

The key is in the simplicity, each humble ingredient allowed to speak for itself. To be regarded as a bona fide Neapolitan pizza, the tomatoes for the sauce must be either San Marzano tomatoes or pomodorini del Piennolo del Vesuvio; the cheese must be mozzarella di bufala campana (a protected designation of origin cheese) or fior di latte (a cow's milk mozzarella registered as a traditional specialty guaranteed aka TSG);

...And the dough must be made from medium-strength, finely ground wheat flour with no more than 20 percent being strong flour, fermented 8-24 hours, usually kneaded by hand, be no more than 3 millimeters thick, and baked in a 430-490-degree Celsius wood- or gas-fire oven (with a domed roof so most of the heating comes from the top) for just 60-90 seconds.

The result? An elastic, fragrant crust that bloats with a leopard-spotted char.

Neapolitan pizzas are also usually personal pizzas, foldable, with minimal add-ons so that the dough, cheese, and sauce shine.

As surely Asia's most awarded pizzeria, Bottega holds the title of Top Pizzeria Asia Pacific, Best Pizzeria China and 14th Best Pizzeria from 50Top Pizza, plus Three Slices from Gambero Rosso – the equivalent of receiving three Michelin stars in the world of Napoli pizzas venues.

This is owed to the fact that they've been pumping out their pizzas since 2014 using the same 36-48-hour fermented, 80 percent hydration dough recipe that's been passed down for three generations in the Salvo family... dating back to Nonno Salvo, who owned a pizzeria in Naples back in 1928. The current menu offers more than 20 pizza topping options, all baked in Bottega's custom-built pizza oven.

Other commendable Naples-style pizza can be found at Mammamia, Ragù, Bella Vita, and an artisan Naples-California amalgamation style at sister venues Pizzeria S and Scarpetta.

If you go...

Bottega, 1/F, 101B, K.WAH CENTRE, 108 Xiangyang Rd N., by Huaihai Rd M. 襄阳北路108号101B嘉华中心1楼, 近淮海中路.

Bottega Jing'an, 457 Shaanxi Rd N., by Beijing Rd W. 陕西北路457号, 近北京西路

Pide – Garlic

An oblong-shaped Turkish flatbread, pide comes with a diversified array of toppings: cheese, spiced sausage, minced meat and spinach.

Pide can be found anywhere from upscale restaurants – where fermented dough rivals even the best artisan Italian pizza – to neon-lit, late-night takeaway kebab shops – where one would devour this gut-busting, grease-dripping snack concealed by the dark of night.

The wheat-based dough pide is most often open-faced, yet sealed versions can be found, and is normally cooked in wood-fire or stone ovens found across Turkey, Armenia and the Middle East.

At Turkish mainstay Garlic, one of the top-ordered dishes since opening way back in 2012 is the aformentioned pide, available in cheese, beef, mushroom, spinach, mixed (beef tenderloin, mushrooms, spinach, and an imported white Turkish soft cheese similar to mozzarella called kaşar peyniri), and even lahmacun (see above). Here, the dough is made of high-quality flour and proofed for 30 minutes.

Pressed to about one-centimeter thick, the pide sides are folded over, hand-crimped along the edges, and painted with an egg and water mixture to ensure a glossy finish. Baked for just 10 minutes, the resulting crust is more flatbread-esque, chewy and dense to compliment the toppings of diners' choosing.

Pide can also be found at Efes and Pasha.

If you go...

Garlic, 698 Yongjia Rd, by Anting Rd,永嘉路698号, 近安亭路.

Roman Pizza al Taglio – Bambino

For pizza geeks like us, ones that stay up late at night pondering dough fermentation speeds, crust digestibility and the optimal ratio of yeast-to flour, the perfect pie begins with the crust. And Roman pizza al taglio (or pizza by the slice) – that's customarily baked in massive cast iron rectangular pans, sliced haphazardly into squares, and sold by weight at pizzerias around the country) – is all about said crust.

Similar to Florentine schiacciata, Roman pizza al taglio boasts a thinner, focaccia-like crumb made with potato for added fluff, malt powder, and a daub of honey that caramelizes for a shatteringly crisp crust. The higher hydration dough and extended fermentation time means each slice is at least two fingers thick (should be spelled with a double "c"), yet airy, topped with assorted accoutrement.

While anyone can do pizza, no one in Shanghai is doing it quite like Chef Lucky Lasagna at Bambino. It's like a Detroit pizza meets an upside Sicilian in carb heaven, and they decide to move to Rome.

It deserves a cult following.

Chef Lucky's base is pizza bianca bread, as it's called in Rome, with four options available at lunch, or for delivery all day – transported to your door in a humidity-resistant box to maintain that requisite crunch. Like any good Roman pizza al taglio shop, flavors rotate often, keeping it fresh, seasonal, and enticing.

In short, this is not your average slice.

If you go...

Bambino, 600 Shaanxi Rd N., by Xinzha Rd 陕西北路600号,近新闸路.

Tonda Romana – Bella Vita

While pizza al taglio may share the Roman pizza limelight, pizza tonda Romana deserves equal praise. This flat, round, thin crust pie is cracker-like, rolled out until its totally flattened, instead of stretching.

Most commonly found at sit-down pizza restaurants in Rome (as opposed to slice takeaway joints), the dough has a higher quantity of oil that allows the brittle outer crust to singe, the sound of which is described by the Roman dialect onomatopoeic word "scrocchiarella."

Bella Vita serves up two styles of pizza, of which Roman-style thin crust is one. Using 5 Stagioni flour – the pizza is fired quickly at high heat, finished with all manner of the highest quality Italian ingredients: DOP tomato sauce, spianata spicy salami, culatello cooked ham, grana padano cheese, buffalo mozzarella, confit garlic, and the like.

If you go...

Bella Vita, 555 Haifang Rd, by Xikang Rd, 海防路555号, 近西康路.

Sicilian – Zup Pizza Bar

The precursor to the Detroit pizza, the Sicilian, known by locals as sfincione in Italian, has a spongy focaccia-esqe, thick crust, plus a square base sauced with tomato and finished with local cheese, like caciocavallo or pecorino. Also known as sheet-pan pizza, the dough is shaped in the pan itself, with the crust pinched at the edges, and the sauce, cheese, and toppings added next.

Beloved for its golden, swollen crust, the secret to good Sicilian pizza is in the par-bake, which allows the crust to stabilize without overcooking the toppings.

While Zup Pizza Bar crashed into the Shanghai pizza scene with the city's first ever tavern-style pizza (see below), they also make the city's top-quality Detroit-style 'za. The process begins with a blend of two high-gluten flours, coupled with a very high hydration rate of 82%. After calculating the desired dough temperature using inputs (like room temperation, flour temperature, starter room rempterature, and friction factor of the dough mixer), the dough is bulk fermented for 48-96 hours.

The dough is then portioned into Chicago-sourced baking pans where it rises for another 3-5 hours. Before baking, the dough is dimpled for a better crumb structure, then par-baked, allowing excess steam to escape.

Zup takes it a step further by making their Sicilian slice "upside down," meaning the cheese (a combo of mozzarella and cheddar) is placed directly on the par-cooked dough, and the sauce is then slathered on top, the reverse of the routine pizza layering technique.

Detroit pizza toppings range from house fennel sausage with giardiniera; to vodka sauce with meatballs and ricotta; to white sauce with mashed potato, smoked bacon and ranch dressing; (and more)!

If you go...

Zup, No.101, Room 4, 457 Shaanxi Rd N., by Beijing Rd W., 陕西北路457号4幢101, 近北京西路.

Tavern – Zup Pizza Bar

While some may balk, objecting that real Chicagoans don't eat thick crust pizza, they're wrong – of course they do. But the go-to, neighborhood pizza consumed on the daily will forever and always be the thin crust.

And this is not just in Chicago; this underrated pie that is finally receiving its long overdue recognition is a Midwest staple found in local pizza taverns from the lakes of Minnesota to the dairy farms of Wisconsin, from the cornfields of Iowa to the central plains of Ohio.

For those from the American Midwest, tavern-style pizza is a cracker crust pie – sliced into slapdash squares – concealed by scorched-edge pepperonis, pools of fat forming in each spicy meat-ring's center, at a neon-lit dive bar with Neil Diamond's "Sweet Caroline" playing in the background.

It's nostalgia on a plate.

At its best, tavern-style pizza defies the laws of physics with both crunch and flavor in such a small density of bread. The crust is not just crisp, but complex, with its own personality that can't be found in any other pizza across the globe.

And the process to make said crust at Zup Pizza Bar – the posterchild for tavern-style pizza in Shanghai – is a scientifically calculated method, a multifaceted math equation that sounds like something only Bill Nye the Science Guy could cook up.

The inputs of daily air, dough and flour temperatures are balanced by the friction factor to determine the necessary water temperature that ensures the pizza dough begins its 72-120-hour cold fermentation process at exactly 76 degrees Fahrenheit.

These inputs are meticulously recorded daily to manage calculated tweaks to the scientific method for discovering the perfect crackly canvas on which pizza toppings rest.

The pizzas meet their maker in a customized, double-decker Thunderbird oven imported from the USA that can fire up 12 pies at a time, cooking low and slow for 5-6 minutes to guarantee those chewy, yet not-too-filling, slices.

Each 14-inch pizza is presented with up to two servings of two weeks-pickled and hand-chopped daily giardiniera – an Italian relish of vinegar-pickled veggies adopted by Chicagoans, a city renowned for an Italian immigrant population that has so heavily influenced its food scene.

Zup goes through 50-80 kilos of the stuff a week. So yeah, it's a Chicago pizza necessity.

Toppings include the standard – pepperoni, cheese, and sausage – to the creative – white sauce with pancetta, mashed potatoes, and ranch (known as the Walter White); sausage fennel and herb (known as the Grand Fenneli); and the owners' namesake pie (the Hou-Lee Trinity) with red sauce, vodka sauce and pesto.

The Hai sports bar also showcases some solid cracker crust style 'za in an equally expansive lineup of flavors.

If you go...

For Zup's address, scroll up to find it in the Sicilian pizza section.

Tlayuda – Tacolicious

A common street food – or antojito – found predominantly in Oaxaca, the tlayuda is Mexico's take on a pizza.

The base is a large baked and dried masa corn tortilla smeared with refried beans and stacked high with lettuce, salsa, guacamole, quesillo (Oaxacan stringy cheese), and diners' choice of seared meat (usually tasajo – a type of semi-cured beef; chorizo; or grilled, thinly sliced steak).

The tlayuda is roasted over open-flame, folded over onto itself, with the meat served on the side. Patrons ordinarily alternate between bites of this "Mexican pizza" and the grilled meat of their choosing, a street snack served late into the witching hour.

At the ever-popular Tex-Mex establishment Tacolicious the menu sees the team's take on the tlayuda, one that features a shmear of refried beans, avocado, cherry tomatoes, jalapeños, pico de gallo salsa, and a generous sprinkling of mozzarella and cheddar, all atop a plancha-toasted 12-inch flour tortilla (which is key for crunch) with diners' choice of protein. Options span steak asado, birria, grilled shrimp, al pastor, sweet heat hot fried chicken, chili con carne and more.

If you go...

Tacolicious, Room 104-105, 34 Yuyao Rd, by Xikang Rd, 余姚路34号1幢104-105室, 近西康路.