Prepare the Dried Chiles: Start by removing the stems and seeds from the guajillo, ancho, and optional chiles de árbol. Heat a dry skillet over medium heat and toast the chiles for about 20–30 seconds on each side until fragrant. Transfer them to a bowl, cover with hot water, and soak for 15–20 minutes until pliable.

Sear the Beef Chunks: Pat the beef chuck roast dry, season with kosher salt and black pepper. In a large skillet over medium-high heat, add vegetable oil and sear the beef chunks for about 3–4 minutes on each side until browned. Transfer to the crock pot.

Build the Flavor Base: In the crock pot, place the halved onion and head of garlic around the beef. Add the bay leaf, cinnamon stick, whole cloves, thyme, oregano, cumin, and salt. Pour in enough beef broth to almost cover the meat and add apple cider vinegar.

Sauté Vegetables for the Sauce: In the skillet, sauté the chopped onion and garlic until golden brown, then char the halved tomato for an additional 3–5 minutes. Transfer this mixture to a blender.

Blend the Chile Sauce: Drain the soaked chiles and add to the blender with the sautéed vegetables. Blend until smooth, adding reserved beef broth as needed for consistency.

Combine the Ingredients in the Crock Pot: Pour the blended chile sauce over the seared beef, gently stir to coat. Set your crock pot to LOW for 8–10 hours or HIGH for 4–6 hours until beef is tender.

Shred the Beef and Prepare the Consommé: Remove the beef from the crock pot and shred it. Ladle some cooking broth over the shredded beef and reserve fat from the broth for later use.

Warm the Tortillas: Wrap tortillas in a damp towel and microwave for 30–45 seconds until warm. Alternatively, heat in a skillet.

Assemble and Fry the Tacos: Dip each tortilla into the reserved consommé, fill with shredded beef and cheese, fold, and cook in a skillet for 2–3 minutes until crispy.

Serve with Toppings and Consommé: Serve tacos hot, topped with onion and cilantro, along with small bowls of consommé for dipping.