SANTA ANA, Calif. — In a cramped kitchen behind a counter adorned with a smiling gold Buddha, restaurateur Henry Le fishes a fist-sized beef bone out of a cauldron of simmering broth before turning his attention to bins full of sliced beef, pork, chicken and tripe.

It's the midafternoon lull, but in another hour the numbered, laminate-topped tables at Pho Tau Bay restaurant will be crammed with customers craving the only item on Le's menu: pho.

The traditional Vietnamese noodle soup, pronounced "fuh," is a staple here in Santa Ana's Little Saigon, home to the largest population of Vietnamese outside Vietnam. In a neighborhood where tiny mom-and-pop shops crowd three and four to a city block, Le's rich, beefy broth has been unofficially declared some of the best pho around.

"It's easy to make, but hard to make good. There are too many pho restaurants around here," said Le, grinning under his paper chef's hat. "Looking for the good place, now that's something different."

Cheap, simple and nutritious, Vietnamese consider the soup of broth, rice noodles, meat and vegetables the ultimate comfort food, the Vietnamese version of a bowl of homemade chicken noodle soup.

For expatriate Vietnamese from Washington, D.C., to Honolulu, it is also a treasured social and cultural touchstone that keeps business booming and memories of home strong, all while providing a culinary link that helps straddle the cultural divide between immigrants and their American-raised children.

"There are so many restaurants," said 18-year-old Ann Nguyen, who stopped for a bowl of beef pho at Luc Dinh Ky restaurant with her brother and his girlfriend. "It's like Starbucks, only times 10."

Though the exact origins of pho are somewhat murky, most agree that the simple soup first took root near Hanoi, in northern Vietnam, shortly before the turn of the last century.

Some believe that the name "pho" is a corruption of the French word "feu," for fire — a reference to a classic French dish called pot-au-feu that was introduced to Vietnam by French colonists.

Others think pho was copied from a Chinese dish and later tailored to Vietnamese tastes.

The recipe traveled to south Vietnam in 1954, when more than 1 million refugees fled forces that had taken power and forced out the French. The broth was a hit in Saigon, where residents embellished the dish by cramming it with more meat and serving the noodles with garnishes such as fresh basil, lime juice, bean sprouts, cilantro and hoisin sauce.

Even today, thousands of miles from Vietnam, connoisseurs say they can taste subtle, regional variations in the broth of the establishments that line the streets wherever Vietnamese have settled.

"The flavor of the broth is the main secret of each place," said Nicholas Nguyen, a manager at Brodard Chateau in Santa Ana, Calif., a fusion restaurant that has put its own French twist on the traditional soup. "Competition exists a lot in Little Saigon and people tend to have a lot of choices, but they will come to a place because they like the broth."

Chefs put high priority on making a clear, pure broth, sometimes taking more than five hours to simmer it with huge hunks of marrow-packed beef, chicken or pork bones and an array of delicate spices. The pho also must arrive at the table piping hot, so the basil and cilantro are flash-cooked when added by the customer.

"Presenting the noodle soup is an art, I think," said Chau Dang Haller, a co-owner of Brodard Chateau, a restaurant popular with Vietnamese and non-Vietnamese alike. "My chef will be there usually as early as eight in the morning to start the soup and he's usually done by two or three. It takes his attention 100 percent."

For Le, pho is more than just good flavor — it's also a link to his family's past.

His family owned a pho restaurant in Hanoi but moved it to Saigon in 1954. There, the restaurant flourished and still operates under the name Pho Tau Bay — the same name Le chose for his own American noodle shop.

Many of the customers who flock to his Orange County establishment remember his family's business on Ly Thai Road in Saigon, now called Ho Chi Minh City. His front window and business cards are printed in Vietnamese with the words, "Like the original Pho Tau Bay restaurant on Ly Thai Road in Saigon," and photos of the original Pho Tau Bay adorn the walls of his restaurant.

Now, his daughter hopes her children will someday continue the family legacy. On a recent day, they slurped soup and watched the Cartoon Network under their grandfather's watchful eye as they waited for a ride to an after-school martial arts lesson.

"We work together," Kelly Le said. "Sometimes it's noisy a little bit, but it's OK. We work together and make the restaurant go up.