It’s Monday night and Tommy’s Mexican Restaurant is hopping. The bar, tucked behind a partition to the left of the front door, is standing-room only. The booths are filled with hungry customers.

Servers jot orders on their notepads and run aromatic plates of enchiladas and Yucatecan tamales to their guests, whose eyes grow wide when their food is delivered. Others chat in between crunchy bites of tortilla chips and sips of margaritas.

At the bar, people clink their glasses together, echoing “cheers” or “salud” as they taste their lime-colored cocktails. Some nose their tulip glasses of neat Tequila and ponder its terroir, seriously studying the characteristics that define this category of spirit.

At the center of it all is Julio Bermejo, a spectacled man with dark hair, who dons a black button-up shirt marked with the restaurant’s logo. He makes his way up and down the bar, pulling bottles from the shelf, asking people if they’ve tried this or that Tequila, smiling for occasional photos and chatting with regulars who have been coming to the bar for years. He orchestrates the dynamics of the bar with ease, something that he has earned with years of practice. He carries on several conversations at once, never missing a beat and rarely forgetting a name. He monitors the bartenders and watches the pace of the restaurant, often stepping into the dining room to give hugs or shake hands. He’s the lifeblood of Tommy’s — both an internationally renowned Tequila expert and a staple of the neighborhood.

Tommy’s is in the Outer Richmond, past the steel buildings that stretch into the San Francisco sky. It’s far from the cars and buses that clog the downtown streets during rush hour. Instead, it’s in an unassuming building on Geary Boulevard marked only by a red neon sign. It sits across the street from St. Monica’s, a white church that doubles as a grade school (the one that Bermejo attended as a child).

Tommy’s has been around since 1965 when Bermejo’s mother and father, Elmy and Tomas, started serving food from their native Yucatan. It’s been a hub for various communities ever since, providing people with meals, employment, good Tequila and respite from the rhythm of their daily lives.

Tomas was born in 1932 in Oxkutzcab, Mexico. As a child, he did what he could to make ends meet. “From what I gather, my father was fairly poor,” says the younger Bermejo. Tomas would sell his harvest from chicle trees or water he had gathered to other town residents. He came to the United States as part of the Bracero Program.

The literal translation of “bracero” means “one who works using his arms” and was a term used for a manual laborer. The program was started in August 1942 when the U.S. and Mexico signed the Mexican Farm Laborer Agreement. This agreement called for several things, including decent living conditions for immigrant laborers (which meant access to sanitation, food and shelter), minimum wage of 30 cents an hour, and changed labor from seasonal to year-round.

The Bracero Program was extended in 1951 with the Migrant Labor Agreement and then enacted as an amendment to the Agricultural Act of 1949. It ended in 1964. During the course of its life, it sponsored over 5 million “guest workers” but was criticized harshly as legal slavery and for the actual working conditions it spawned. After the program was dissolved, many workers stayed in agriculture while others headed to cities. Tomas spent 10 years in the program, and was one of those who was city-bound.

Tomas married his wife, Elmy, before joining the Bracero Program. He would visit his wife when time and money allowed. The couple had two children while he was in the program and three more when he was able to move them up to San Francisco. (Julio Bermejo still remembers meeting his two oldest siblings for the first time as a child.)

Tomas used the money he had saved to open his first business, Elmy Café, on McAllister Street, and later to buy the building that would become Tommy’s. He and Elmy worked hard to provide their family and staff with the opportunities that they did not have in Mexico.

When Tommy’s opened in 1965, Tomas and Elmy ran the business without help. “It was literally my mother and father who did everything,” Bermejo says. “My father bought the food, cooked it, washed dishes and took care of maintenance. My mother did the administration. I honestly don’t know how they did it, but they managed.”

Eventually, some family members made their way to San Francisco, including Bermejo’s Uncle Oscar, who is Tommy’s longest running employee and still works the floor. The rest of the family would help when and where they could, including with design. “Our original sign was painted by my uncle, the husband of my father’s sister. He painted a roast beef and two enchiladas. I’ll forever remember that,” Bermejo says.

Bermejo’s earliest memories are of Tommy’s. He was just a year old when his parents opened the restaurant. “There were photos of me in diapers in here,” he says. He remembers the jukebox and sneaking into the open kitchen, where his father was cooking, to run across the street to play. He had mixed feelings about growing up in a restaurant family. While the restaurant provided a safe haven and financial stability for his family, he was expected to help out as much as possible when he was old enough. “I peeled potatoes and carrots, grated cheese and ran errands to pick up things,” he says. He learned some hard but formative lessons as a child at Tommy’s.

As the youngest of five, he watched his siblings move beyond the family business. He longed to follow suit and was excited to head to college. He completed a year at San Francisco State before transferring to UC Berkeley. He lived at home while in school and worked at the restaurant on weekends, unable just yet to escape the life he longed to leave.

Bermejo earned a bachelor of science degree in political science and foreign service in 1988. He wanted to work for the State Department as a diplomat. He took the foreign service exam but was unable to pass the oral interviews, dashing his dreams of a life in politics. He cut his losses, and while he figured out his next steps, he returned to Tommy’s.

After Tommy’s received its liquor license in 1976, the family put a blended margarita on the menu with mixto Tequila — made from a mixture of agave and other ingredients like corn, wheat and even artificial additives. In 1989, shortly after he graduated, Bermejo’s friend introduced him to Herradura, a Tequila made from 100 percent blue agave. “It blew my mind,” he says. This purer type of Tequila is vastly more representative of the land on which the agave is grown, and the experience became the catalyst for a deep relationship with Tequila. Bermejo began to look at what types of liquor the restaurant was carrying. “Our bar looked like most bars of the era,” he remembers. “We had every crème de whatever, bourbon, and really weak Tequila.”

After discovering Herradura and taking a closer look at Tommy’s products, he started visiting Mexico frequently to tour distilleries, meet producers and bring back bottles. “I started going every six weeks on my own dime. They would talk, and I would listen,” he says. He learned about the land, the production and Mexican hospitality. A passion was ignited, one that he has never lost.

He took his newly acquired knowledge back with him to San Francisco and used it behind the bar. He educated his customers about the virtues of 100 percent agave Tequila. People weren’t always receptive to sipping the spirit neat, so Bermejo used the margarita as a vehicle to illustrate the different characteristics of each expression. He also simplified the original version of the cocktail, using only Tequila, lime and agave syrup. This became what is now known as the Tommy’s Margarita, which felt revolutionary and later earned him international acclaim.

Bermejo’s dream of being a diplomat may have been lost in the traditional sense, but his career took on a new life when he began advocating for good Tequila. His curation and work to educate people on the social, cultural, environmental, economic and political aspects of the spirits category gave him pride. People from all over the world made trips to Tommy’s to sit in front of him and taste whatever he was pouring. His family’s business enabled him to create a meaningful professional career: “It doesn’t go unappreciated that people appreciated the work that we do.”

Not only did Tommy’s become a refuge for Bermejo, it also became one for Tommy’s employees. When Tomas was running the restaurant, he made an effort to hire people from the Yucatan, creating, as one 2002 Chronicle article put it, “an informal safety net for dozens of friends who have come to Northern California to start a new life.”

To this day, the family has a legacy of retaining staff for years, something that is unheard of in most other restaurants. Bartenders, servers and cooks stay for decades. Bermejo’s Uncle Oscar has worked there for 45 years while others have been there for over 20. In turn, his longtime employees make an effort to return the favor. One of his cooks maintains his connections to the Yucatan and helps out at the Mexican Consulate. The restaurant strives to welcome people in and give them a change for the better. “My employees may not speak perfect English, but the experience is always genuine,” Bermejo says. “You can tell when a place has soul. You can’t quantify it, but you can feel it. It’s being part of a community.”

As Bermejo created a stable professional home for himself and his employees, the restaurant was becoming a refuge for his guests. Tommy’s is the buoy that got some regulars through divorces, career changes and other personal turmoil. It’s the place where people want to celebrate good news, come for comfort, reconnect with old friends and learn something new about Tequila.

One of the ways in which Bermejo achieved this was through his Blue Agave Club. The program was designed as an educational component of tasting and was modeled after a punch-card program at Raleigh’s, a bar where he drank in college. For a $10 application fee, customers are enrolled in the club and work their way through three levels. The first two levels, Masters and Ph.D., require the tasting of 35 Tequilas each. An exam is required to pass the Ph.D. level, with a score of at least 80 percent. The last level, Demigod, requires traveling to Mexico with Bermejo. “It took a while to work, but now we have over 8,000 members of the club,” he says. “There are over 800 Masters. It gives people incentive to try brands they’ve never heard of. That’s been really cool.”

At Tommy’s, two strangers could be sitting next to each other, realize they are both working their way through the program and strike up a conversation. Community is formed over mutual interest in Tequila.

The restaurant allowed Tomas and Elmy to make a good living and provide for their five children. In turn, those children created successful careers for themselves. They were able to employ family and friends from Yucatan, so they too could prosper in San Francisco. Tomas cultivated an environment where people felt welcome.

Julio Bermejo is able to carry on the spirit of his father, who passed away in 2011. For Bermejo, Tommy’s became a place where he could find his voice and share his love of Tequila and Mexico with the world. Ultimately, Tommy’s became a place that allowed Bermejo to realize the career aspirations of his youth. In 2001, he became Mexico’s sole U.S. Tequila ambassador. His years of educating himself and others about Tequila turned into a political career of sorts, one that he takes seriously. His passion for the blue agave spirit has not waned, evident in the way he works the bar if you happen to catch him there on a busy Monday night.

Shanna Farrell is an interviewer at UC Berkeley's Oral History Center, where she works on a variety of projects and specializes in contemporary cocktail culture. She is the author of “Bay Area Cocktails: A History of Culture, Community and Craft.” Email: food@sfchronicle.com