Our latest installment of Quick Bites brings us to the UWS for tacos and a tiny backyard.

Since moving to Harlem from Mexico City about 15 years ago, Victor Martinez has done just about every front-of-the-house restaurant job you can think of, from dishwasher to runner to server to manager. But the dream has always been to open his own place, and with The Calaveras on the Upper West Side, Martinez has now done exactly that.

Partnering with his best friend from Mexico, chef Francisco Flores, and his wife Nicole Soto, Martinez and crew bring a lot of light and life to their semi-subterranean space near the north end of Columbus Avenue. And while the immediate neighborhood has changed considerably since I lived up the block in the early 1990s, there's still a vital, old-timers sidewalk social scene around these parts. Soak it in while you're here; this is what large swaths of UWS used to feel like.

From the street all you see of The Calaveras is a tiny bar and a table or two, but it's unclear if these are actually used for anything other than folding napkins. A hidden stairway at the back of the street-level space takes you to where the real action is, a dining room downstairs that seats about 65 at tables, an ample bar, and a charming little backyard patio. The decor is all sombreros and skulls (the namesake calaveras), the service cheerful and fast, and the music jumps from uptempo Mexican guitar classics to contemporary college indie stuff and back again. It's easy to imagine the place packed with Columbia kids.

The Calaveras menu plays it pretty safe, but there's enough variety among these greatest hits to keep you coming back. A pair of vegetable-based dishes made me especially happy, including a lovely Roasted Corn Soup, thick with avocado chunks and almond slivers, a bit of serrano salsa complementing the natural sweetness with some heat. The Quesadilla de Huitlacoche also showed excellent balance, the thick tortilla shell fried to a pleasant chewiness and stuffed with mushrooms, gooey Chihuahua cheese, and a vibrant tomatillo mix.

If you enjoy downing a bowl of melted cheese to start your meal (and if you don't, I'm sorry to hear that), you can order the Queso Fundido with confidence: the Calaveras version is deeply satisfying, particularly when brightened by the kitchen's excellent salsas. More first-rate sauce awaits you with another Mexican-menu stalwart, Echilades de Mole, which is rich and lively enough to elevate the mostly mediocre chicken inside.

Like that somewhat forlorn bird, the pig within the Al Pastor tacos disappointed with its dryness, but again, the guajillo sauce brings some sweet heat, and the pineapple adds enough overall juiciness to salvage the dish. Nothing could save the Pescado tacos, however, which were straight-up bitter in every bite. Given that most people will gravitate to the reasonably-priced taco section of the menu (and that chef Flores and crew are obviously skilled cooks), they should probably try to fix both of these dishes immediately. For dessert, the Calavares Flan is an entirely acceptable entry into the canon.

With its lively, comfortable room and mostly first-rate food (pending adjustments), Calaveras has a chance to become a new neighborhood favorite, both for longtime residents and the more transient Columbia community. Let's hope they pull it off.

The Calaveras is located at 949 Columbus Avenue, between 107th and 106th Streets, and is open Sunday through Thursday from noon to midnight, and on Friday and Saturday until 2 a.m. (646-484-6533; thecalaverasnyc.com)