Toast the dried guajillo and ancho chiles in a dry skillet over medium heat for 1-2 minutes per side until they puff slightly and smell fragrant. Remove stems and seeds if a milder heat is desired. Then soak the toasted chiles in hot water for 15 minutes until softened.
6 pieces dried guajillo chiles, 4 pieces dried ancho chiles
Heat a heavy-bottomed pot over medium-high heat and sear the beef chuck roast for 3-4 minutes per side until a dark brown crust forms. Do not move the beef around while searing to ensure proper caramelization.
3 lbs beef chuck roast
Blend the softened chiles with garlic, onion, tomatoes, cumin, oregano, cloves, vinegar, and 1 cup of beef broth until smooth. Strain the sauce through a fine-mesh strainer to remove chile skins and seeds. Pour the sauce over the seared beef in the pot.
6 pieces dried guajillo chiles, 4 pieces dried ancho chiles, 1 tsp cumin, 1 tsp oregano, 2 whole cloves, 1 whole onion, 6 cloves garlic, 2 whole tomatoes, 0.25 cup vinegar, 2 cups beef broth
Add the remaining beef broth to the pot, cover tightly, and braise in a 300°F oven for 3-4 hours until the beef reaches an internal temperature of 195°F and shreds easily with a fork. Check at 3 hours and continue cooking in 30-minute increments if still tough.
3 lbs beef chuck roast, 2 cups beef broth
Remove the beef from the pot and let rest for 10 minutes. Shred with two forks while still warm. Dip corn tortillas briefly in the consommé, fill with shredded beef, fold, and pan-fry in a hot skillet for 1-2 minutes per side until crispy edges form.
3 lbs beef chuck roast, corn tortillas
