One late May afternoon in a small kitchen on To Ngoc Van Street in Hanoi's Tay Ho District, Dang Van Thai is tossing a dough ball into the air, spinning it on his fingertips.

With his chef's instinct and experience, he knows this batch is perfect for pizza.

After topping it with tomato sauce, cheese and other ingredients, he slides the pizza into a stone oven. Three minutes later it emerges with a puffed-up crust and crispy base - hallmarks of naturally fermented pizza.

"Just by looking at the leftover crust, I know if the customer is satisfied," the 39-year-old chef says.

Through the window, he receives an empty plate and a nod of approval from co-founder Tran Van Duong.

Dang Van Thai, co-founder of a pizza restaurant in Tay Ho District, Hanoi. Photo by VnExpress/Phan Duong

Raised in the impoverished countryside of Ly Nhan District, Ha Nam Province, Duong and Thai dropped out of school early to survive.

At 12 Duong became a street kid in Hanoi, with Thai following two years later.

By day they roamed the streets with baskets, taking on odd jobs - shoe shining, selling newspapers or peddling CDs - and at night rented a spot in a migrant workers' slum if they had money; if they did not, they slept under bridges.

One summer afternoon in 2003 on Thuy Khue Street, Thai, then a scrawny boy, wandered without a single customer for shining shoes.

Spotting a tall foreign man, he hesitated, torn between apprehension and the need to eat. "No risk, no food tonight," he told himself, mustering the courage to offer a shine.

The man was Jimmy Pham, founder of Koto, Vietnam's first social enterprise, dedicated to training disadvantaged youth in hospitality and culinary arts.

"I was impressed that Thai only charged VND2,000 and did not overcharge a foreigner like some others," Pham recalls.

As he paid, he pointed to a building behind him and asked, "Would you like to learn a vocation there?"

That night in a sweltering fiber-cement-roofed rented room, Thai, Duong and their friends huddled over a Koto flyer. Its promise of free education and meals seemed too good to be true.

"After five to seven years of scraping by, we were exhausted by our aimless lives," Duong recalls.

The group took a leap of faith and applied.

A few months later Koto called them for entrance exams. Weeks later, while wandering the streets, Thai heard someone yell. Turning, he saw Jimmy, grinning: "Congratulations, you passed!"

Thai says: "From being street kids, we got rented rooms, meals and a bicycle each to ride to school like proper students. [It was ] pretty cool."

The 18 months at Koto were tough. Beyond academics they also learned English, service etiquette and soft skills, and worked with restaurants, hotels, international schools, and foreigners. Trading their freewheeling street life for strict discipline and roll calls was jarring. On some days they felt like quitting.

Koto splits trainees into waitstaff and chefs. Thai and Duong both found their passion in the kitchen.

Dang Van Thai (L) started working at 14 while Tran Van Duong (R) left school at 12 to make a living in Hanoi. Photo provided by Duong and Thai

In 2006 the duo graduated, and got jobs at two different places.

Seven years later they pooled their savings to open a bakery. Launched one summer the business struggled and folded up quickly.

They went their separate ways again, working to pay off debts.

In 2017 their entrepreneurial spirit reunited them, and they opened a Middle Eastern restaurant in the West Lake area.

To keep it afloat, Thai worked side jobs while Duong ran the kitchen and operations.

Six months in, the restaurant stabilized, and Duong called Thai back.

Two years later it was thriving with 17 staff and five delivery people, and they opened a second branch.

But Covid-19 brought disaster.

With foreign customers gone, both restaurants bled money, forcing them to sell one.

It was during these hard times that they realized Vietnamese customers were their bread and butter.

Shifting to a fast-food model with pizza, chicken, pasta, and drinks proved a winning move.

Initially they served industrial pizza.

Each discarded crust pained Thai, who felt they were "half-serving" customers. He dove into research, learning artisanal fermentation techniques from foreign forums.

For nearly two years he toiled daily with five kilograms of flour and yeast to perfect a crispy, chewy subtly sweet crust.

"It took that long for Thai to convince me to ditch industrial pizza," Duong recalls. "I resisted, fearing we'd lose regulars."

In late 2022 they changed the menu. In 2023 they slashed pizza prices. By 2024 they launched frozen pizzas that retained the fresh-baked crispness.

Since October 2024 their restaurant has been buzzing every night, and they have been selling over 2,000 pizzas a month.

Some people have offered to buy their recipe, but they declined.

Nguyen Thi Hue, Thai's wife, says she cried and begged him not to start a third venture.

"You just cleared your debts - now you're risking it again?" she had asked him.

But Thai persuaded her, saying, "Let me try one last time."

She says: "Luckily, they succeeded this time."

Dang Van Thai (L) and Tran Van Duong review their plans for opening a second pizza restaurant in Hanoi in 2025. Photo by VnExpress/Phan Duong

Throughout, Jimmy Pham quietly followed his former students' progress.

The Koto founder marvels at how the dusty-footed shoe-shine boys of yesteryear became resilient entrepreneurs chasing their passion.

"What moves me most is they've kept the KOTO spirit- 'Know one, teach one' - helping others as they were once helped."

After multiple setbacks, Thai and Duong learned they did not need a vast menu - just one exceptional dish to succeed.

"We're not trying to reinvent pizza, we just want to make a truly delicious one for Vietnamese people," Thai adds.