Since its stripped-back beginnings, the new wave of so-called street food has had a major impact on global restaurant culture. It began as an antidote to the formal dining scene of the 1980s and 1990s, with makeshift markets popping up in derelict car parks and vendors building hype on Twitter. Now it is ubiquitous. There has been an explosion of modish food courts and walled-off markets and hundreds of permanent restaurants, which started out as street-food traders.

Street food – and it seems a stretch to define it as such these days – has influenced everything from the dominance of casual dining to the rise in restaurants that specialise in highly elevated versions of single dishes. Chefs who forged their reputations on tiny food stalls have built slick and influential food businesses. How did taco trucks and burger vans wind up having so much sway in the food industry?

One of the best case studies in how a street food trader can build a brand – and an empire – is Bao in London, which opened its fifth restaurant, Café Bao, in King’s Cross this month, and will open Boa Noodle Shop in Shoreditch in a few weeks’ time. It started life as a six-seater stall at Netil Market in Hackney, east London.

A post-graduation road trip eating the best street food in Taiwan inspired university friends Ms Erchen Chang, Mr Shing Tat Chung and Mr Wai Ting to create the concept. “During our trip, we encountered both traditional gua bao and pillowy steamed baozi,” says Chang. “We were mesmerised by both of them and wanted to bring them together.”

Back home, the trio hosted a handful of pop-ups before opening their market stall in 2013. A tiny kitchen forced the team to focus on perfecting just one menu item: their signature cloud-like bao with fillings such as sticky slow-cooked pork or fried chicken. “Starting out as a street food stall allowed us to focus on perfecting our bao, making it better and better,” says Chang.

Relentlessly honing a single dish is a defining characteristic of the most successful street food traders. The same year Bao was born, Mr David Carter was importing a 4.5 tonne smoker from Houston, Texas, to launch Smokestak at a Street Feast market in London. His slow-cooked smoked brisket buns with pickled chilli soon became the stuff of legend.

“They were the dish that built the brand and the business and eventually funded Smokestak [Carter’s permanent restaurant, opened in 2016] in Sclater Street,” says Carter. “Four simple ingredients, better than the sum of their parts, dished out to tens of thousands during our Street Feast days. To this day, I still think it remains our most accomplished dish.”

As the street food movement gathered pace, chefs around the world began pushing the boundaries to elevate seemingly simple dishes beyond recognition, and the food establishment started to pay attention. Mr Chan Hong Meng, of Liao Fan Hawker Chan, moved to Singapore aged 15 and obsessively perfected the recipe for what’s become his signature – soy sauce chicken and rice, served from a hawker stall in one of Singapore’s many covered food markets.

“Singapore is famous for its Hainanese chicken and rice, but soy sauce chicken and rice didn’t have much of a following back then,” he says. “I decided to pursue and perfect the art of cooking soy sauce chicken rice,” he says.

The dish – chicken marinated in soy sauce and herbs for several hours, then slow-braised until it’s ridiculously tender – led to Liao Fan Hawker Chan becoming the first hawker stall to be awarded a Michelin star, in 2016. It costs less than three Singapore dollars and is frequently dubbed the world’s cheapest Michelin-starred meal.

In Los Angeles, meanwhile, Mr Wes Avila turned tacos on their heads to earn the approval of the food elite. Before founding Guerilla Tacos in 2012, the Mexican-American chef cooked in some of the world’s best fine dining restaurants and trained in Paris under Mr Alain Ducasse. When he swapped Michelin-starred kitchens for his own taco truck, he became famous for serving genre-busting sea urchin tostadas or foie gras tacos, and Guerilla Tacos won accolades from Mr Jonathan Gold, the first food truck to receive a review from the esteemed Los Angeles Times food critic.

“My formal trading melded very well with my food truck,” says Avila. “I approached the food in a careful and thought-out way to be able to put up the very best version of street food possible.”

How does a successful street food startup become a fully fledged restaurant? For the team behind Bao, the key has been maintaining the meticulous approach they used when perfecting their bao recipe in the early days.

“The food scene in London is always exciting, but also competitive,” says Chang. “This raises standards and pushes people to innovate. The way we do things is through a design-centric approach, which always comes back to that attention to detail.”

There are now five Bao restaurants across London, a delivery business, Rice Error, and an upmarket eatery, Xu. Café Bao King’s Cross opened in May and is the team’s largest and most ambitious project to date.

“The menu is inspired by western-style cafés, seen through Bao’s lens,” says Chang. “Some of my favourite dishes are the ham hock congee pie and XO lobster head with chips. They’re a marriage between western-style aesthetics and heartwarming Taiwanese flavours.”

This month, Bao Noodle Shop opens. It will serve rich beef noodle broths inspired by the street food traders of Taiwan. It’s a long way from that first six-seater stall.

Street food was once a way for up-and-coming chefs and food entrepreneurs to make a name for themselves without the financial commitment of a bricks-and-mortar restaurant. But then the trend went mainstream and investors started to take notice. Permanent, covered food market behemoths, such as Kerb, Boxpark or Pergola in London and Time Out markets in Lisbon and London, are opening everywhere. Diners have an insatiable appetite for increasingly diverse flavours, from Filipino small plates at Bong Bong’s in London to Korean-Mexican at Kogi BBQ in Los Angeles (both started out as food trucks).

Instagram has played its part. Snaps of mochi soft-serve ice cream cones or overstuffed burgers have more instant cachet than pictures of a five-course sit-down tasting menu. Since winning its Michelin star, Liao Fan Hawker Chan has opened five locations in Singapore and franchise outposts in Taiwan, Malaysia, Australia and Thailand. Guerrilla Tacos has grown into three sites and Avila has published a cookbook.

“I think the movement has changed how the mainstream consumer looks at food,” Avilia says. “If you look closely at what chain restaurants are doing now, it’s pretty clear they’re jumping on food trends created on the streets. The movement is still growing, in LA and in other parts of the world.”

Chefs are even pivoting from a more formal offering to so-called street food. Mr James Lowe, of Flor in London, opened a takeaway pizza pop-up, ASAP Pizza, during lockdown. From those heady early days, street food has become so mainstream, so heavily marketed and so professional, that it’s lost its original meaning.

“In its prime, the energy and vibe at Street Feast was electric,” says Carter of the nights he spent at the buzzy east London street food market. But that doesn’t mean those starting out at markets and street food stalls are no longer exciting. They’re simply part of the fabric of how the restaurant industry works today.

“There are so many so-called pop-ups that are actually just street carts selling street food now,” says Avilia. “It’s very interesting to watch it grow and evolve.”

Perhaps to label it “street food” is no longer relevant. This is just diverse, challenging and exciting food – served on the street or not – and it’s here to stay.