Lamb Barbacoa

Ingredients

• 6 dried guajillo chiles, stemmed, seeded and torn into ½-inch pieces (¾ cup)
• 1 (2½- to 3-pound) boneless leg of lamb, fat cap trimmed to ⅛ to ¼ inch
• 6 garlic cloves, peeled, divided
• 5 teaspoons kosher salt, divided
• 2½ teaspoons dried Mexican oregano
• 2 teaspoons cider vinegar
• ½ teaspoon pepper
• 2 whole cloves
• ¼ teaspoon ground cumin
• 1 (15-ounce) can chickpeas, undrained
• 8 ounces red potatoes, unpeeled, cut into ½-inch pieces
• ½ small white onion, halved through root end
• 2 carrots, peeled and halved crosswise
• 2 bay leaves
• 2 dried ancho chiles, stemmed, seeded and torn into ½-inch pieces (½ cup)
• 6 ounces tomatillos, husks and stems removed, rinsed well and dried
• 1 small plum tomato
• ¼ small white onion, quartered through root end
• 2 garlic cloves, unpeeled
• 1–2 dried arbol chiles, stemmed (optional)
• 1¼ teaspoons kosher salt
• ½–1 teaspoon cider vinegar (optional)
• Pinch to ½ teaspoon sugar (optional)
• 24 (6-inch) corn tortillas, warmed
• Finely chopped white onion
• Thinly sliced radishes
• Fresh cilantro leaves
• Lime wedges