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A First Look at the Modern Mexican Cuisine of Siempre J.B.

Posted on June 27, 2024   |   Updated on September 30, 2025
Rob Kachelriess

Rob Kachelriess

A platter of five salsas at Siempre J.B.

Spicy salsas. (Rob Kachelriess/City Cast Las Vegas)

It seems like we can’t go too long without talking about UnCommons in the Southwest Valley. After the closure of The Sundry last week, an ambitious new Mexican restaurant opens July 3, giving the mixed-use complex a more upscale, but approachable dining option.

🍽️ Stylish Destination

Siempre J.B. is easily the most formal restaurant at UnCommons with a stylish 100-seat dining room, an 18-seat bar, and a patio by a roll-up, garage-style door for those rare moments in Vegas when the weather is right for comfortable al fresco dining.

🇲🇽 Mexican Inspiration

Chef Roman Andres draws on his Mexican heritage, taking inspiration from Mexico City, Oaxaca, and his own Pueblo background. Dried chilis are used frequently, making everything a touch spicer across the board.

🥩 Steak and Sizzle

The carne asada is served as an entree — flame included 🔥— with the grilled marinated skirt steak (in place of the more common flank steak) brought to the table on a sizzling hot plate alongside thick cuts of grilled squash.

🌮 Tacos y Tacos

Guests are encouraged to choose their own taco platter from six different options. The carnitas (shredded pork) is hard to beat, featuring a sweet-and-spicy balance of tomatillo sauce and charred pineapple 🍍

A chicken-stuffed quesadilla.

More quesadilla, please. (Rob Kachelriess/City Cast Las Vegas)

😋 Amazing Appetizers

Begin your meal with dishes designed to share, including a collection of salsas (showstoppers in both taste and presentation) with house-made chips and chicharrones. Coastal regions are well represented too with five versions of ceviche on the menu. Moist taquitos are wrapped in lettuce for added crunch and the quesadilla (stuffed with adobo chicken) is one of the best I’ve tried in Vegas.

🐟 Fresh Ingredients

Sourcing is key. Much of the fish is flown in from Japan. The shrimp and corn (used to make tortillas) come direct from Mexico. Fresh produce is brought in straight from Salinas farms with no stops along the way.

🥃 Exclusive Tequila

Siempre J.B. teamed up with Dos Caras to develop the restaurant’s own exclusive Reposado blend. It’s ultra smooth and delicious neat. Try a few more varieties in a series of tasting flights.

🤑 Test Your Luck

A special coin comes with the Patrón-fueled Buena Suerte shot. Use it to win a coin flip and you’ll earn an extra shot on the house. Bring it back and try again on a return visit.

🍹 More to Drink

The bartenders have a deep selection of craft cocktails (made with house-made syrups and juices), including La Rosa, which combines sotol and mezcal with hibiscus (in a glass skull! 💀) for a unique grassy flavor. A few Mexican wines are on standby too. If you’re skipping the booze, try a from-scratch Agua Fresca or creamy Horchata.

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