It sounds simple enough — a restaurant that focuses on Mexico’s most basic, and iconic, food stuff and adult beverage.

But while what one finds within Tacos x Mezcal, at 39 E. 18th St., might appear to be a bit basic, it is far from simple.

The menu is suitably concise: eight varieties of street tacos, 10 appetizers, two desserts. For the thirsty, it lists 18 foreign and domestic beers, four signature margaritas and four signature cocktails.

“When we were planning this,” said Mario Guajardo, one of the owners, “we were tempted to do a big menu. But we managed to tamp that impulse down, to stay disciplined and focused on our original idea, to give people sophisticated street food and fine mixology in a place where they will feel comfortable hanging out for a while.”

This spot on the corner of 18th Street and Boston Avenue has been many things through the years, most notably the nightclub SRO. The owners of Tacos x Mezcal have done major renovations and remodeling to transform it into a quirky cantina, with tree branches made into light fixtures, a wall decorated with crosses, and playful works by local artists.

The interior can be a little close and a little loud, which Guajardo said was part of the plan, to encourage people to not only talk among themselves, but also make friends with whomever may be sitting close by.

It certainly worked during a recent visit, when a lady at the table next to our party inquired about a drink one of the group had ordered, and we ended up cracking wise with each other for the rest of our time.

The drink in question was one of the signature cocktails, the Jalapeño Prickly Pear ($12), a concotion of sotol mezcal, lime, orange and the titular fruit that was remarkably fresh-tasting and, as he told to woman who inquired, “dangerously delicious.”

Equally tasty was the Spicy Guajillo Mango margarita ($10), with the peppered rim giving most of the spicy to the well-balanced, not too sweet drink.

We started with two of the shareable plates: the guacamole con cavier ($8), topped with generous dollops of paddlefish roe; and the queso fundido ($6), a hot cast-iron skillet of chihuahua cheese to which we added chunks of pork belly (carne asada and braised short rib are additional choices).

It came with three small corn tortillas, but it was just as tasty scooped up with the complimentary chips and augmented with a touch of the three salsas. Our favorite was the dark red sauce that was an intriguing blend of sweet and heat.

The guacamole was adorned with curls of cucumber, slivers of onion and rings of jalapeño, with the roe adding as much a textural element to the creaminess as flavor. My suggestion that we try another guacamole, this one with chapulines, which are crickets, was met with.....well, crickets.

We sampled a fair number of the taco offerings, which range from $3 to $5 each, and include a vegan and vegetarian option. The tacos are served on thick slabs of wood, which can fill up a table top quickly.

The taco de pastor ($3.50) had tender cubes of marinated pork and a thick strip of grilled pineapple. It was good, but the other two I tried were better. The taco de camarón ($5) was the biggest surprise — it is essentially a jalapeno popper on a tortilla, with the jalapeno replaced with a roasted Anaheim chili, the stuffing dominated by shrimp, and all wrapped in well-cooked bacon.

More conventional, but equally good, was the taco de pescado ($5), with a piece of swordfish that had been coated in a tempura-like batter and fried, under a pile of shredded red cabbage and carrot, with a swipe of guacamole to hold the fish in place and a chipotle aioli. The blend of cold and hot, creamy and crunchy, was delicious.

Tacos x Mezcal is the creation of a pair of father-and-son entrepreneurs, Mario and Nicolas Guajardo, and Joseph and Jojo Hull.

The Hulls have owned the buildings on the northwest side of the intersection since the mid-1970s, when they opened Boston Avenue Market. The previous occupant of the Tacos x Mezcal space was looking to leave, and “we wanted to do something different than just have another nightclub here,” said the younger Hull.

“My wife and I had recently been to Mexico, where we had all kinds of amazing street food,” he said. “We thought this would be something we could bring to Tulsa.”

Hull said the Gaujardos, who have business interests in Mexico, came in with the concept for what Tacos x Mezcal would become. The Gaujardos also brought in executive chef Sebastian Renner, a Mexico native who has worked in fine dining around the world. Renner was in town recently to help craft the restaurant’s new brunch menu, which launched on Mother’s Day.

“This is comfort food,” Renner said, “made with the best possible ingredients, and executed well. We have a good team here that I know I can rely on to keep everything exactly as it should be.”

There is also room for expanding the menu somewhat, with dishes such as esquites con tuetano, or Mexican street corn with roasted bone marrow.

As for the “fine mixology,” Mario Guajardo said one thing he hopes Tacos x Mezcal does is open people’s sensibilities to the vast range of mezcals that are available.

Mezcal is something of an umbrella term for any beverage brewed from the agave plant. Tequila is a very particular type of mezcal, prepared in specific ways, while mezcal can be crafted in many ways.

“Depending on how it is processed — where the plants were grown, how it was cooked, all those things — mezcal can have all kinds of flavor profiles,” Guajardo said. “In that way, the best mezcals are very much like good Scotch. And we want to feature the full spectrum of mezcal here.”