It’s in the heart of New Mexico but completely south of the border in spirit. If the phone cards, paletas and corrido CDs don't give it away, the green tomatillo salsa should. On weekends Ruby's turns the dining service up a notch, serving tamales and menudo. Though spiced simply, the barbacoa is rich, soft and full of complexity. For 10 bucks you get a pound of meat plus an assortment of salsas, chopped onions and cilantro, grated cabbage and lime wedges. Pints of red and tomatillo green are sold in tied-off baggies for $1.25 each. The order comes with a stack of fresh corn tortillas, but consider buying a kilo more for $2.25. With the proper reinforcements, that pound of meat will multiply into a lot of juicy tacos.