ATTENTION, diners navigating a nation of struggling restaurants: a whole universe of new properties is secreted in the feverish brain of Michael Bao Huynh, if only he can get to them all.

With five Vietnamese-inspired restaurants in New York already, some only a few months old, he has plans for as many as 10 more — noodle bars, sandwich shops and fine-dining spots in Manhattan, Queens and Brooklyn. And that’s not to mention the restaurant in Oakland, Calif., opening next year, noodle and sandwich shops outside New York, a Vietnamese cooking school in Da Nang and a future flagship restaurant in Ho Chi Minh City.

Some bloggers, observing Mr. Huynh’s diminutive but surging restaurant collection, have mocked his supposed imperial ambitions.

“I don’t see this as an empire,” said Mr. Huynh, 44. “I’m just a small businessman.” Though he added, “I’m a gambler — when you’re hot, you have to play more.”

Mr. Huynh — a former boat person who learned to cook by his mother’s side at her restaurant in Saigon — has been able to capitalize on New York’s infatuation with a cuisine for which he has proselytized. His mini chain of Baoguette shops cash in on the banh mi sandwich craze and dish up pho, the fragrant Vietnamese noodle soup New Yorkers have learned to love.

And as a former contractor who can design both menus and restaurants, building many places himself to save on costs, Mr. Huynh has been able to turn hard times to his advantage.

Right now he is reaching for low-hanging 10-to-20-year leases all over town. “Before the recession, chefs like me had no chance,” said Mr. Huynh (pronounced win, with an initial hint of an “h”). “Rents were too high and everyone wanted key money — $100,00 or $200,000. But now you can get a half-million-dollar restaurant for free, and rents are at least 20 percent down.”

He sighed. “Next year the rents will be up,” he said in his voluble but strongly accented English, “and guys like me will have no chance.”

In his rush to grab the moment, though, Mr. Huynh has also stirred a spicy stew of partnerships, some of which have bubbled over in conflict. Some who know him question whether his world is both overextended and undermanaged. "Michael is talented — a mover and shaker,” said Chris Johnson, a former partner in Bao 111, one of Mr. Huynh’s first restaurants, and Bao Noodles. “But he has no loyalty, he’s not trustworthy and tends to move too quickly from project to project. That will be his downfall at some point."

Mr. Huynh countered that their failed partnership did not deserve his trust or loyalty and that like dozens of the city’s chef-owners with multiple restaurants, he goes all-out to create a new property, haunting the kitchen, then delegating to his staff. “Each place you open,” he said, “you get smarter and smarter.”

Drew Nieporent, Mr. Huynh’s partner in Mai House, which cycled through chefs and then shuttered as Mr. Huynh shifted his attention to other restaurants, said, “I opened 33 restaurants in 25 years — so I am not the pot to call the kettle black,” adding, “but when you go this fast and it doesn’t work right, you are not going to create a lot of friends.”

Mr. Huynh said he thinks of Mr. Nieporent as a friend, and would work with him again. (Mr. Nieporent observed radio silence when apprised of this.)

Since opening Mai House, Mr. Huynh has also opened Bia, a 55-seat beer garden at 154 Orchard Street; 10-seat Baoguette at 61 Lexington Avenue; 25-seat Baoguette Café at 37 St. Marks Place, Pho Sure, a 24-seat shop at 120 Christopher Street, and BarBao.

Mr. Huynh’s plans include OBao Noodles & Grill, an 85-seat outpost at 222 East 53rd Street; a 30-seat dessert and snack place, Spot (with the pastry chef Pichet Ong) at 13 St. Marks Place; a larger Baoguette at 9 Maiden Lane; B Clinton, a 38-seat French-accented Asian restaurant at 6 Clinton Street with a $29 three-course prix-fixe menu, and by summer an unnamed indoor-outdoor seafood restaurant (with a subterranean karaoke component) with 200 seats on the waterfront in Williamsburg, Brooklyn. A wannabe two-star for the Upper East Side is on the drawing board as are several downtown Vietnamese burger joints that Mr. Huynh said he is toying with naming Baoger.

To visit with Mr. Huynh as he juggles urgent mobile calls from all his kitchens and construction sites at his table in his year-old BarBao at 100 West 82d Street is to sit in on a surging restaurant reality show. While many chefs begin their mornings buying produce, Mr. Huynh’s days begin at 8, ordering construction materials for job sites. Afternoons and evenings, he is likely to be monitoring his restaurants, as he was at 2 p.m. recently in Pho Sure and at 10 p.m. in BarBao when a reporter made surprise visits.

Mr. Huynh, the oldest of six children, was born Huu Huynh, and the Bao nickname/brand adhered to him as an infant when he was very ill, said Mr. Huynh’s 40-year-old sister, Thao Quan, a senior marketing manager for HSBC bank in Manhattan. “In Vietnamese culture, if a child is sick, the monks give him a different name,” she said, adding, “the family knows him as Bao.”

Mr. Huynh’s father, Hi, was a successful architect in Saigon before the American helicopters withdrew in 1975. In the aftermath, architectural commissions evaporated, and Mr. Huynh’s mother, Ngia Nguyen (“a great cook,” Ms. Quan said), opened a restaurant so the family could survive. Mr. Huynh grew up in the kitchen. “I learned how to work incredibly hard,” he recalled.

Ultimately his father encouraged the family to leave Vietnam “because there was no future then,” Mr. Huynh said.

Ms. Quan said of her siblings that “four of us escaped by boat, and Michael left first,” adding: “We had terrible fear, because my uncle’s family tried it — and their boat sank. They just disappeared.”

Mr. Huynh recalls the menace of towering waves before being saved by the U.S.S. Midway in 1982. Eventually he found a foster family in the village of Jeffersonville in Sullivan County, N.Y.

He went by the name Michael, he said, “after Michael Jackson” (he used the name on his naturalization certificate in 1988) and worked while at Jeffersonville High School. His salvation, he said, was his job as a dishwasher in Ted’s Restaurant on Main Street.

“Soon he was one of the cooks on the line,” said Tom Savopoulos, a son of the late Harry Savopoulos, who owned the restaurant. “He was a great kid, well-spoken, ambitious — and always working very, very hard.”

Mr. Savopoulos said his family eventually took in Mr. Huynh, who occasionally cooked Vietnamese classics at home. Mr. Huynh sponsored Ms. Quan and her sister Paulette after they survived their own escape from Vietnam, she said, “and we managed to get the entire family here.”

But Jeffersonville “was a sleepy little town, and Huu had ambitions,” Mr. Savopoulos said. Eventually, when the sisters found foster sponsors in Brooklyn, Mr. Huynh joined them and began paying for architecture studies at the New York Institute of Technology by cleaning bathrooms at night and cooking for roommates and neighbors.

In the late 1980s, he said, he was shot by accident in a gang-related shooting in Queens. "New York was a jungle of gangs then,” he said, “and I was hanging out with friends, partying. I was young — it was a mistake." Recovering, though, "made me much stronger." After working as an architectural expediter, he opened his own construction business, 7 Design, building restaurants and dreaming about opening his own.

Mr. Huynh was a contractor for Nello Balan’s now-defunct Nello SoHo restaurant “and one day he came in with his bag of ingredients and cooked a terrific meal,” said Mr. Balan, who owns celebrity hangouts in Manhattan and Southampton, N.Y. “I was amazed by his talent. We became friends.”

Mr. Huynh’s first restaurant, Vicala, at 111 Avenue C, opened during the downtown meltdown after Sept. 11, 2001. “I had to find partners to survive,” he said of “Chris and Chris” — Chris Johnson and Chris Andrews, former waiters from the halcyon early days of Balthazar, who went on to manage restaurants including Town and Bond Street.

The three opened Bao 111 in what had been the Vicala space, winning a star from Frank Bruni in The New York Times in 2004. "The Bao name became famous because of this collaboration,” Mr. Johnson said, adding that “Michael was an unknown cook and we tweaked him, both inside and outside of the kitchen to make him better."

Bao 111 closed last year but Bao Noodles, a spinoff on West 23d Street that the three men opened in 2003, is going strong without Mr. Huynh.

“The Chrises” trademarked the name Bao 111, Mr. Huynh said, without his knowledge — something they deny — and prevented him from using the Bao name in other ventures; they say they had the right to.

Mr. Johnson’s version goes like this: "Things went well for a while,” but he added: “His involvement in other side projects meant that he was never there, so the kitchens fell apart — and we had to fix it." They bought him out.

Soon Mr. Huynh was helping build the $2 million Mai House in TriBeCa with Mr. Nieporent, which won two stars when Mr. Bruni named it one of the 10 best 2007 restaurants. But it never made enough money and closed earlier this year. “If he is going to make a significant contribution,” Mr. Nieporent said of his former partner, “he has to have one restaurant that he spends time in, and that people like — and that stands the test of time.” Some thought BarBao — which Mr. Bruni gave one star for its “ambitious and nuanced” cuisine earlier this year — could be that restaurant.

But one of Mr. Huynh’s BarBao partners, Paul Zweben, said “we have a chef de cuisine who is very good, but we would love for Michael to be there more.” Of Mr. Huyhn’s ambitions, Mr. Zweben said that “if he has the infrastructure, he can make it work and if he doesn’t, it can all come tumbling down.”

“You can only slice a chef so thin.”