Come on a Saturday afternoon, when this neighborhood butcher shop and grocery store sets up a mesquite charcoal grill in the parking lot. Inside, buy your marinated tender beef from the butcher counter, plus a bag of flour tortillas, fresh salsa, a couple of avocados and some little green onions. Then get in line, and wait for your turn at the asadero, a mesquite-charcoal-fueled grill where they'll cook it up perfectly for you, free of charge. You don't need to bring along the address; just find the general neighborhood, and follow the fragrant billowing smoke. Buy enough to pick at leftovers all week, and the wait for Saturday won't seem so long.