First, I remove stems and seeds from guajillo, ancho, and arbol chiles, give them a quick rinse to clean off dust. Then I simmer them in water until soft. While that’s happening, I roast tomatoes, onion, and garlic under the broiler until they have charred spots—this adds smoky sweetness and depth to the sauce.
Once the chiles are softened, I put them in the blender with about a cup of the chile-soaking water. I peel the roasted garlic and add tomatoes, onion, spices (cumin, oregano, cloves, cinnamon, ginger), salt, pepper, beef broth, apple cider vinegar. I blend everything until very smooth—this becomes the flavorful sauce base for the birria.
Next I place chunks of beef chuck roast into the slow cooker. I pour the blended sauce all over, tuck in some bay leaves, cover, and cook low for 8-9 hours (or on high for about 4-5) until the meat falls apart. After cooking, I discard bay leaves, shred the meat with forks, then return it to the sauce in the slow cooker so it soaks up all the juices (the consommé). Then it’s ready to serve.