1Cut 5 lbs of boneless chuck roast into 3-inch pieces.
2Boil in 8 cups of water with ½ white onion, 1 head of garlic, 1-2 Tbsp salt, and 4 bay leaves for 1 hour over medium-high heat, skimming off the fat.
3In a separate pan, lightly toast 10-12 NM chili pods or guajillo, 3 ancho chiles, 6-8 Arbol chiles (optional), and 6 garlic cloves for 2-3 minutes until fragrant.
4Transfer the peppers and garlic to a blender with 6-8 peppercorns, 5 whole cloves, 2 cups of water, and the onion and garlic from the pot.
5Blend until smooth and strain into the pot with the beef.