Slow-Cooker Red Chile-Beef Tacos

Place the beef stock in a microwavable bowl, and microwave on HIGH 2 minutes. Stir together the chiles, hot beef stock, onion, cumin, tomatoes, and garlic in a 5-quart slow cooker. Sprinkle the steak with the salt and pepper; nestle into the chile mixture in the slow cooker. Cover and cook on LOW until the beef is tender, about 8 hours.

Transfer the steak to a plate, reserving the chile mixture in the slow cooker; shred the steak with 2 forks. Skim the fat from the surface of the chile mixture, and transfer the chile mixture to a blender. Remove the center piece of the blender lid (to allow steam to escape); secure the lid on the blender. Place a clean towel over the opening in the lid (to avoid splatters). Process until smooth. Pour the mixture into a saucepan; cook over medium-high, stirring occasionally, until the sauce has thickened, about 15 minutes.

Combine 2 cups of the sauce and the shredded beef in a large bowl, tossing to coat. Reserve the remaining sauce for another use. Divide the beef mixture evenly among the tortillas. Top evenly with the cilantro and radishes, and serve with the lime wedges.