Prepare the dried chiles: Remove the stems and seeds from the guajillo, ancho, and árbol chiles. In a dry skillet over medium heat, toast each chile for 20–30 seconds on both sides until fragrant. Once toasted, transfer them to a bowl, cover with very hot water, and soak for 15–20 minutes until pliable. Drain the chiles before blending them into a rich sauce.

Brown the beef: Pat the beef chuck roast dry with paper towels and season generously with salt and pepper. Heat 1–2 tablespoons of vegetable oil in a skillet over medium-high heat. Sear the chunks of beef for 3–4 minutes per side until a golden-brown crust forms. Once browned, transfer the beef to your crock pot.

Build the flavor base in the crock pot: Nestle the halved onion and the head of garlic around the seared beef in the crock pot. Add the bay leaf, cinnamon stick, whole cloves, thyme, oregano, cumin, and salt. Pour in enough beef broth to nearly cover the beef and drizzle 2 tablespoons of apple cider vinegar over the top.

Make the chile sauce: In the same skillet used for searing, sauté the roughly chopped onion and garlic over medium heat until golden, about 5 minutes. Then, add the halved tomato cut-side down, cooking until charred. Blend this mixture with the soaked chiles, smoked paprika, chili powder, cinnamon, sugar, and ½ cup of reserved beef broth until ultra-smooth. Strain if desired.

Combine chile sauce with the beef: Pour the blended chile sauce into the crock pot over the beef. Stir gently to ensure even distribution. Taste and adjust seasoning as needed.

Slow cook the birria: Cover the crock pot and set it to cook on LOW for 8–10 hours or HIGH for 4–6 hours. Ensure the beef is fork-tender at the end.

Shred the meat: Once cooked, carefully remove the beef from the crock pot and discard the aromatics. Use two forks to shred the meat into chunky pieces.

Prepare the consommé for dipping: Skim off and reserve any excess fat from the top of the broth, adjusting the seasoning as needed. Ladle the broth into small bowls, garnishing with cilantro and lime wedges.

Prep toppings and tortillas: In small bowls, arrange chopped onion, cilantro, and lime wedges. Warm the corn tortillas.

Assemble and fry the birria tacos: Heat a skillet over medium heat. Dip each tortilla into the consommé, then place it in the skillet. Add cheese and shredded birria meat, folding the tortilla into a half-moon shape. Fry for 2–3 minutes on each side.

Serve: Plate the crispy tacos and top with onion and cilantro. Serve alongside bowls of consommé for dipping.