Step up to the cafeteria-style counter off to one side in this Mexican grocery and order a burrito with any of about a dozen fillings that vary from day to day. If they're offering the guisado of beef in colorado sauce (a rich red mole), grab it. It's a revelation: smoky, spicy, silky, deep. Or choose pollo a la diabla, a very hot, very tender chicken-and-chili mash that leaves you panting. Or go for the pork in a green tomatillo-based sauce--springy, tart, citrusy...yum. Heck, if they're all on the day's list, splurge: At less than $5 a pop, you can freeze what you don't eat and taunt your friends with your after-bar snack options.