Lamb Barbacoa Tacos

Name: Lamb Barbacoa Tacos
Ingredients: 5 dried ancho chiles; 1 bone-in lamb shoulder (8 to 10 pounds); 2 tablespoons salt; 1 tablespoon freshly ground black pepper; 2 tablespoons chipotle chile in adobo; 5 celery stalks, roughly chopped; 5 cloves garlic, smashed; 4 ripe tomatoes, diced; 2 carrots, roughly chopped; 3 sprigs fresh thyme; 3 sprigs fresh oregano; 5 bay leaves; 2 medium onions, cut into chunks; One 12-ounce bottle dark beer, such as Negra Modelo; 2 cups chicken stock or water; 1/2 teaspoon chile powder; 1 bunch fresh cilantro, chopped; Corn tortillas, for making tacos; Chile De Arbol Tomatillo Salsa, recipe follows; One 10-ounce package Cotija; 1 bunch radishes, chopped; 6 cloves garlic; 5 tomatillos, husked; 5 plum tomatoes; 1 whole onion, quartered; 5 dried chiles de arbol; 3 dried ancho chiles; 3 dried guajillo chiles; 2 tablespoons chopped fresh cilantro; 1/2 tablespoon sugar