The Vietnamese community in New York is tiny, accounting for only 0.2 per cent of the city's population. Still, Vietnamese food has had its moments over the years, with occasional hot restaurants becoming cultural touchstones - from Indochine, the fashion-world clubhouse that opened downtown in 1984, to Le Colonial, which brought a bit of French nostalgia to Midtown in the 1990s, to Bunker, a more contemporary sensation with a hip-hop soundtrack and industrial setting, which shut down in Brooklyn three years ago.

Now, a new wave of scrappy Vietnamese restaurants, exploring the remarkable diversity of the country's cooking, has captured the city's imagination - and its social media feeds.

At Mắm, on the edge of Chinatown, chef Jerald Head, a native of San Antonio, Texas, and his Vietnamese-born wife, Nhung Dao, have designed an entire restaurant around a single dish, bún đậu mắm tôm - a communal feast of rice vermicelli, fried tofu and various offcuts of pork (grilled intestine, blood sausage and poached pork belly, in this case), with plenty of fresh herbs. This classic street food from Hanoi is dressed in a potent dipping sauce of funky fermented shrimp paste that might be gently described as an acquired taste, and divides even Vietnamese diners. "It's like seeing a new colour, it's so intense," says Head.

Head has been hooked on bún đậu - as the dish is known in its short form - since first tasting it nearly a decade ago. "My understanding of Vietnamese food was phở and bánh mì," he says. "I was like, 'Holy shit, this is so different.' I was absolutely blown away."

It's not just solid, real Vietnamese food we're selling. It's the whole experience

Pining for the dish back in New York, the couple developed their own version at home, making their own tofu with a machine they imported from Vietnam. They later opened Mắm as a twice-a-week pop-up to showcase their rendition. Three years ago, the pop-up became a permanent restaurant, with low-slung plastic tables and chairs brought in from Vietnam spilling onto the sidewalk from a sliver of a dining room. Despite the uncomfortable seating and limited menu, Mắm has been packed since opening day. "It's not just solid, real Vietnamese food we're selling," says Head. "It's the whole experience."

Last year the couple opened a natural wine bar, Lai Rai, just up the street. Soon they'll have a third business on the block: a café specialising in bánh mì, launching later this year.

Ha's Snack Bar - another restaurant run by a bicultural couple just around the corner - also started as a pop-up before settling into a space late last year. Anthony Ha, a first-generation Vietnamese-American, does most of the cooking; his wife, Sadie Mae Burns, oversees the dining room, natural wine list and the desserts. The couple and their restaurant have garnered mountains of press. Reservations have been almost impossible to come by. All the attention, it seems, has become overwhelming. In the spring they reached out to New York Magazine's restaurant critic, pleading with him not to file a review (the magazine published a rave nonetheless). Sure enough, when I squeezed into a perch at the window for dinner recently, Ha and Burns let me know they weren't open to chatting. Their food, though, turned out to be worth the hype.

This is bistro cooking, essentially, shot through with potent Vietnamese flavours: a jolt of tamarind in the butter-sopped escargots; big hits of hot chilli in an extra-jiggly pork terrine; plenty of bright herbs in a hand-cut steak tartare smeared on crusty baguette. The menu, which changes frequently, occasionally swerves south-east Asia entirely: a light dish of steamed skate in fish sauce one night giving way to a comforting - and very Mediterranean - bowl of soupy risotto with hunks of braised lamb.

Plans are under way to move the restaurant into a much larger space on the Lower East Side, relieving some of the pressure (the working name is Bistro Ha). Ha's Snack Bar, meanwhile, will continue operating as a drop-in bar for wine and snacks.

A short walk uptown, Bánh anh Em, which opened to long lines in the East Village last autumn, doesn't take reservations; waits for a table can run as long as two hours at night.

For chef Nhu Ton, a native of central Vietnam who moved to the US 13 years ago, and her front-of-house partner John Nguyen, a second-generation Vietnamese American from northern California, opening a restaurant was all about satisfying their own homesick cravings. They started with a modest spot on the Upper West Side, Banh Vietnamese Shop House, which debuted to instant acclaim in 2020. While planning their more ambitious second venture downtown, Ton travelled across Vietnam by motorbike, collecting recipes and sourcing ingredients she now imports directly for her restaurants. "I tried every type of bánh mì I could find," she says.

Bánh anh Em's expansive menu features so many meticulously crafted versions of classic dishes from up and down Vietnam. Big bowls of phở are in the style of Nam Định, the northern province that claims to have invented the dish, with three cuts of beef, slippery rice noodles, and an extra-gingery, umami-rich broth.

"When I first came to America, it seemed like the Vietnamese food was mostly just phở and sandwiches, and they weren't like the ones from back home," says Ton. "That's why I decided to open my own restaurant, with my own vision."