1. In a large pot, add beef, beef broth, guajillo chiles, ancho chiles, onion, garlic, cumin seeds, oregano, salt, cinnamon stick, and bay leaves.
2. Bring to a boil, then reduce heat and simmer for 3-4 hours until the beef is tender.
3. Remove the beef and shred it using forks. Set aside.
4. Blend the remaining broth and solids until smooth. Return to the pot and simmer for another 30 minutes.
5. Heat corn tortillas on a skillet. Dip them in the broth, then fill with shredded beef, cilantro, and onions.
6. Serve with lime wedges and extra broth for dipping.