Prepare the Birria: In a large pot or Dutch oven, combine beef, quartered onion, smashed garlic, oregano, cumin, salt, pepper, and beef broth or water. Bring to a boil, then reduce heat, cover, and simmer for 1.5 hours.
Prepare the Chili Puree: While the beef simmers, rehydrate the chilies by placing guajillo, ancho, and arbol chilies in a bowl. Pour hot water over them and let soak for 15–20 minutes until softened. Drain, reserving the soaking liquid.
Blend the Chili Puree: Transfer rehydrated chilies to a blender, add 1 cup of the reserved soaking liquid, and blend until smooth. Strain through a fine-mesh sieve into the beef pot to remove any skins or seeds. Stir well.
Continue Simmering: Simmer the beef in the chili broth for another 1.5–2 hours, until the beef is fall-apart tender.
Shred Beef & Separate Consomé: Remove beef and shred with two forks. Skim excess fat from the broth (consomé) and ladle some into a separate bowl for dipping.
Assemble Tacos: Heat a non-stick skillet or comal over medium heat. Dip one side of a corn tortilla into the consomé, place the red-stained side down on the skillet, sprinkle cheese, and add shredded birria. Once the cheese melts and the bottom is slightly crispy, fold the tortilla in half.
Fry Tacos: Cook each side for 1–2 minutes until crispy and golden. Repeat with remaining tortillas and filling.
Serve: Serve hot with a side of warm consomé for dipping, garnished with diced white onion, cilantro, and a lime wedge.
Serving and Storage Tips
