Giuseppe Lanzone, left, and his brother Mario Lanzone pose for a portrait near their food stand at the Smithsonian Folklife Festival. (Matt McClain/The Washington Post)

An hour before opening on this last Sunday in June, the Peruvian Brothers kitchen is filled with all the flavors of home.

Steam rises from a large vat of pulled chicken stew, laboriously stirred by one worker with a similarly large spoon. Laid out on the table are trays of peeled sweet potatoes, red onions and yellow peppers. Salsa music blasts from the speakers, and an aproned man whistles along as he sorts shortbread cookies into plastic packages.

These are the foods of Mario and Giuseppe Lanzone’s childhood. The brothers grew up in Peru’s coastal La Punta district, where they ate ají de gallina when they felt sick and alfajores when they wanted a snack. Now they’re serving the spicy pulled chicken stew with baked potato in yellow pepper sauce and sweet shortbread cookie sandwiches with dulce de leche centers, among other Peruvian staples, through Sunday, July 5 at a stand at the Smithsonian Folklife Festival, whose theme is “Peru: Pachamama.”

Founded 2 1/2 years ago, the Peruvian Brothers food truck and catering venture has rapidly risen in the ranks of downtown lunch options. Washington Life magazine recently named it the best food truck in the District, a title that Washington City Paper also handed it last year.

Typically, the truck serves a few hundred people around major Metro stations every day. The daily visitors to their festival stand on the Mall, meanwhile, have numbered in the thousands. Even though the festival is scaled down this year, organizers still expect it to draw more than 300,000 visitors.

Giuseppe Lanzone works to open the Peruvian Brothers food stand at the Smithsonian Folklife Festival. (Matt McClain/The Washington Post)

The quickened pace feels right to Giuseppe, 32, a two-time Olympic rower for the United States who sought a second career that would give him the same adrenaline rush as racing through water. When he returned home to McLean, Va., to which his family immigrated in 1997, he and Mario, 30, immediately started making plans to go into business together.

While Giuseppe had been away for competitive rowing, Mario was honing his culinary skills. He cooked 80 percent of his own meals, and he spent six months scuba diving in the Mediterranean every year, catching flounder that could be sold to make seviche.

Originally, the brothers considered centering their menu on health and fitness. But after realizing that their feelings toward salad were lukewarm, they began thinking about the dishes from their birthplace that they missed most.

From there, a simple menu of classic Peruvian sandwiches was developed, each item a gustatory ode to memories of their plentiful La Punta dinner table. The most popular among these is the pan con chicharrón — fried pork tenderloin with sweet potato slices on a French roll. The sandwich is seasoned with criolla, a salsa made from red onions and lime juice.

As if they didn’t have enough on their plates, the brothers run the business on top of other jobs: Mario is a Mediterranean yacht captain in the summer; Giuseppe is a rowing coach at Georgetown University.

To earn their spot at the festival, the duo competed against seven restaurants, serving four dishes to Smithsonian-appointed judges.

For Mario and Giuseppe, who credit the truck’s success to their family, Peruvian Brothers is as much about heritage as it is about food. The tight-knit Lanzones are out in full force at the festival stand, where the brothers’ parents, uncles and cousins have been lending a hand. One aunt, who runs a high-end catering company in Peru, was even flown in for the occasion. They could really call it “Peruvian Brothers y Familia,” says Fran Holuba, Giuseppe’s girlfriend.

Half an hour before the folklife festival’s 11 a.m. start time, Holuba gives the stand’s young helpers their marching orders. “Darby, what kind of fish is in the pescado sandwich?” she says. The response comes quickly: “Tilapia!” To another, she says, “What do you say when they ask what the Peruvian Brothers is?” Hands reach for the business cards stacked on the counter.

From left, Enrique Vega, Mario Lanzone and Maricheli Montes work at the Peruvian Brothers food stand at the Smithsonian Folklife Festival. (Matt McClain/The Washington Post)

In the kitchen, Giuseppe greets a smiling woman with a cry of “ ¡La jefa!” Because neither brother wants to call the other “boss,” the moniker belongs to their mother, Gisella Lanzone.

Mario, who oversees the cooking, has been at the stand since 6 a.m. doing prep work. He opens the stock room to reveal avocado cases stacked floor to ceiling. More than 2,000 pounds of avocados have been provided by the Peruvian Avocado Commission’s Avocados From Peru exports, from which the brothers developed a menu item — a salad of avocado topped with quinoa and vegetables — to serve at the festival. Avocados From Peru also co-sponsored the festival’s opening reception and will be partnering with the food truck for the next four months.

The difference between Peruvian avocados and those grown in the United States or other parts of South America is notable: Their texture is firmer; the taste is cooler. According to Xavier Equihua, the commission’s president and chief executive, the weather in Peru makes the country “a virtual greenhouse” ideal for avocado production.

The brothers’ recipes have not been modified to accommodate American palates, Giuseppe says. “A first-time customer might not want the red onions, so we’ll put them on the side for him. The next time he comes, he’s asking for extra onions.”

In multicultural Washington, there is lots of room for experimentation. Eager to find restaurateurs equally passionate about sharing their own cultures, Giuseppe has made it his goal to sample food from a different national cuisine every week.

Mario Lanzone works in the kitchen area of the Peruvian Brothers food stand at the Smithsonian Folklife Festival. (Matt McClain/The Washington Post)

One of their first customers Sunday is Lucille Ferraren, a Loudoun County, Va., resident who has wanted to try Peruvian food since her daughter visited Lima. She orders the pan con pescado, a baked tilapia sandwich on a bed of lettuce with tomato and criolla sauce. “I can taste the freshness of the fish,” Ferraren says approvingly between bites.

A long line begins to form, and the Peruvian Brothers are ready. They have 10 cash registers taking 20 orders a minute. One woman asks how much sauce she should put on her pork sandwich, and the cashier responds, “I like to have a lot.”

And so the salsa music plays on. Lanzone family relatives dance as they work, serving stew and tossing salads. Curious customers bite into Peruvian avocados for the first time.

The brothers will follow this current until it doesn’t feel natural anymore. Mario wants to get back to sailing full time one day, either in Peru or the Mediterranean. Giuseppe is helping to coach the Salvadoran national team for the Pan Am Games in Toronto, where he’s headed after the festival. Neither can imagine staying out of the water for long.

Except, of course, when they’re working alongside their family and closest friends, serving the food they grew up on to thousands on the Mall. That’s when the ocean comes to them.