Barbacoa, one of Mexico’s famous slow-cooked dishes, welcomes the addition of smoky chipotle chiles and the rich undertones from Modelo Negra. Serve the meat tucked into warm corn tortillas with a bit of crunchy onion and fresh cilantro.
Heat the oil in the stovetop-safe insert of your slow cooker or a large (12-inch) skillet over medium-high. Pat beef dry with a paper towel, sprinkle generously with salt and add to oil. Cook, turning occasionally, until richly browned on all sides, about 10 minutes. Fit the insert into the slow cooker or transfer the meat to a slow cooker.
Put ancho powder, garlic, vinegar, sugar, chipotle, oregano and cinnamon into a blender. Add 1 cup of water. Blend to a smooth puree. Pour mixture into the slow cooker. Stir in the beer. Cover and slow cook on high until beef is fork-tender, about 6 hours.
Remove meat from pan juices to a cutting board. Skim off any fat from the pan juices in the slow cooker. Taste pan juices. If desired, boil the pan juices in a pan over high heat to concentrate the flavors. Season with salt.
To serve, coarsely shred the beef with two large forks. Arrange beef on a warm platter. Spoon as much pan juices as you like over the beef.
Serve the barbacoa inwarm tortillas topped with onion and cilantro.
OVEN Variation: In a medium-large (4-quart) heavy pot (preferably a Dutch oven), combine the ingredients as described. Add 1 1/2 cups water. Set the cover in place and braise in a 300-degree oven for about 3 hours, adding water occasionally if necessary to ensure the liquid stays at about the same level. Finish as described.