Place the guajillo and ancho chiles in a bowl and cover with hot water. Let soak for 30 minutes, or until softened. Drain and remove the stems and seeds.
In a large Dutch oven or slow cooker, combine the beef chunks, onion, garlic, chiles, cumin, oregano, coriander, cloves, cinnamon stick, and bay leaf. Pour in the beef broth. Season with salt and pepper to taste.
Bring the mixture to a boil over high heat. Reduce heat to low and simmer for 3-4 hours, or until the beef is tender.
Remove the beef from the broth and shred it with two forks.