Rick Bayless' Crock Pot Barbacoa

16 to 20 tacos

Bayless' original recipe was for lamb, but — for the time being — beef chuck is still cheaper than lamb. Guajillo chiles are my absolute favorite, so the braising sauce for this one was right up my alley.

Marinade:

• 2 dried guajillo chiles (stemmed, seeded, torn into small pieces)
• 2 dried ancho chiles (stemmed, seeded, torn into small pieces)
• 2 cloves garlic (minced)
• 1 tbsp cider vinegar
• 1 tbsp dark brown sugar
• 1 tsp salt
• 1 canned chipotle chile in adobo (diced)
• 1/8 tsp cinnamon
• 1/2 tsp dried Mexican oregano

Meat:

• boneless chuck roast (2 to 3 lbs)
• 6 oz beer (Modelo Negro is nice, finish off the bottle yourself)
• 2 bay leaves
• salt
• vegetable oil