Start by bringing a pot of water to a boil. Add the guajillo and ancho chiles. Let them soak for about 15 minutes until they soften.

In a blender, combine the softened chiles, beef broth (about 1 cup), garlic, onion, oregano, cumin, and cinnamon. Blend until smooth and season with salt and pepper.

In a large Dutch oven, heat a tablespoon of oil over medium-high heat. Add the beef chunks and brown on all sides, about 5 minutes.

Pour the chili marinade over the browned beef. Add the remaining beef broth and bring to a simmer. Cover, reduce heat to low, and let it cook for 2.5 to 3 hours or until the meat is tender and shreddable.

Once the meat is fully cooked, remove it from the pot and let it cool slightly. Shred the beef with two forks and set aside. Strain the cooking liquid and reserve for dipping.

In a skillet over medium heat, warm the corn tortillas one by one. Add a generous amount of shredded meat and sprinkle with cheese. Fold the tortillas in half and cook until crispy on both sides, about 2-3 minutes.

Serve the tacos hot, garnished with cilantro, lime wedges, and optional pickled onions. Don’t forget a small bowl of the reserved dipping broth for extra flavor!