There were still two days until the official opening of District Taco’s new outlet in Rosslyn. The employees were getting the feel of the kitchen by making breakfast tacos, the social media team was planning to take photographs, and one guy sat on the floor, testing lights and electrical connections.

Before noon, a few dozen hungry customers showed up, drawn by speculation on social media and signs of activity at the ground-floor, industrial-chic space. Co-owner Osiris Hoil threw open the doors, took a turn behind the counter, then walked around greeting diners.

“They remembered me from the taco cart,” he said of one especially chatty group of office workers.

The cart, a repurposed hot dog stand set up in Rosslyn in 2009, gave District Taco its start. Now it is gone, replaced by seven restaurants, with two more on the way.

Hoil, 33, has gone from cook-cashier-order taker-cleanup man to a white-shirted executive who employs more than 300 people in the District and Northern Virginia.

A view of the meat and beans assembly line section at the District Taco’s newest restaurant. (Linda Davidson/The Washington Post)

“Who would have thought?” he asked, smiling.

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His is a Mexican immigrant’s story. The youngest of three children born to poor farmers in Tekax, Yucatan, he learned to slaughter chickens, pigs and other animals at an early age, and by 9 or 10 was selling newspapers, flowers and popsicles on the street.

“If I needed a toy, I had to work for it, or build it,” he said.

His mother often dispatched him to the garden to pick tomatoes, cilantro and limes for the meals she was creating. If he brought back an unripe ingredient, she sent him outside again.

At 18, Hoil traveled on a visitor’s visa to Denver, where his older brother was working at a restaurant and bar and making enough money to regularly send some home. Hoil got a job at the same bar and worked his way up to cook, learning English from the late-night drinkers. In 2005, he married a waitress named Jennifer, who had grown up in Northern Virginia.

The couple moved to Arlington to live near her family, and Hoil worked construction until the 2008 economic collapse. He was laid off and spent eight months searching for any job, desperate to support himself and his wife, who was pregnant. He became a U.S. citizen in 2012.

Osiris Hoil, co-owner of District Taco. (Linda Davidson/The Washington Post)

One day in 2009, he sat on the porch of his next-door neighbor, Marc Wallace, drinking Coronas. Wallace, an entrepreneur who has started his own software company, asked Hoil what he would do if he could anything at all.

The young immigrant, who had cooked many carne asadas for his and Wallace’s family to share, said he would like to have his own restaurant where he could cook like his mother had. Wallace told him about the food trucks he had seen in Austin and suggested starting there.

Food trucks cost $80,000 to $90,000, which back then seemed out of reach. But Hoil learned that hot dog carts, which could be customized, cost about $25,000.

“We knew Osiris was (is) a trustworthy, hard-worker with a lot of integrity, charisma and passion,” Wallace recalled in an email interview, explaining why he and some other close friends were willing to put up enough money to launch the cart and help Hoil incorporate the business and create a website and logo.

“Our experience starting businesses before allowed us to move fast, and Osiris was able to make some incredible recipes for us to start with,” Wallace wrote. “We knew quickly out the gate that we were onto something special.”

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There were bumps along the way. After naming the business and creating a logo that included an outline of D.C.’s geographic boundaries, Hoil and Wallace learned that the District at the time required food carts to stay in a fixed position. Food trucks, which could move, needed licenses that could be hard to get. Frustrated, the pair turned back across the river to Arlington, where the rules were more lenient.

Hoil hitched the taco cart to the back of his truck and moved it to a curbside spot in Rosslyn, between a Chipotle and Baja Fresh. Aping his mother’s routine, he made one item a day, sometimes pollo asado, sometimes a mole dish (which didn’t sell well), sometimes burritos.

“One guy worked on the 14th floor of one of those buildings, and he would come down every morning to see what I was making,” Hoil said. “He got tired of it and said, ‘Why don’t you put this on Twitter or Facebook?’ I didn’t know what that was — I had a flip phone, not a smartphone.”

So Hoil bought an iPhone, and the customer helped him set up social media accounts. District Taco now has 8,000 Twitter followers, 4,500 Facebook friends and 900-plus followers on Instagram. The chain doesn’t use traditional advertising.

The first restaurant launched on Arlington’s Lee Highway in 2010, followed by others in Dupont Circle, Eastern Market, Metro Center, Alexandria and Dunn Loring. The Rosslyn store, located on Wilson Boulevard below a new Target Express, officially opens on Friday. Next up are restaurants in Skyline and Tenleytown.

Hoil has hired Patriot Contracting, the firm that laid him off, to build the interior of the eateries.

While experts warn that rapid expansion can pose a danger to young businesses, Hoil says District Taco’s finances are sound and his commitment to growth is unflagging.

“The more I hire, the more efficient we become, the more people we serve,” he said. “The company is profitable . . . and I’m not making all these decisions by myself. I have a team, a board of directors, and the team is critical.”

Hoil’s brother, Eric, has moved to Arlington and works as the company’s quality assurance man, making sure the food meets family standards. Their mom, Nelly Hoil, visits three times a year.

She thinks her sons need to use lard and add more salt to the recipes, but Osiris Hoil says his health-conscious American customers would not stand for it.