Start by removing the seeds and veins from the guajillo, arbol, ancho, and pasilla chiles, then rinse them thoroughly.
In a stockpot, combine the chiles with 6 cups of water and bring it to a boil.
Add the quartered onion and the 2 cloves of garlic to the pot.
Include the tomatoes in the pot, then blend the mixture once cooked and strain it through a sieve to create a smooth sauce.
Sear the chuck beef in a pan until it develops a nice crust, then transfer the meat to the pot.
Stir in 1.5 teaspoons of oregano, 3 teaspoons of cumin, black pepper to taste, 2 tablespoons of salt, and 1 bay leaf.
Pour in 3 cups of beef broth, bring the mixture to a medium simmer, cover, and let it cook on low heat for about 3 hours until the meat is tender.
After cooking, remove any excess fat from the broth and shred the meat.
Warm the tortillas on a griddle, dip each one briefly in the broth, fill them with the shredded meat and a spoonful of broth (vidria), then fold the tacos to serve.
