Sear the beef: Begin by heating avocado oil in a cast iron skillet over high heat for 4-5 minutes. Season the chuck roast liberally with salt and pepper, then add it to the hot skillet. Sear the beef for 5-6 minutes on each side until nicely browned.

Combine in the Crock Pot: Once seared, transfer the beef to the crock pot. Add all remaining ingredients—dried chiles, sliced onion, smashed garlic, beef stock, tomato paste, diced tomatoes, vinegar, and spices. Stir everything well to combine.

Cook low and slow: Cover the crock pot and cook on low heat for 8 hours, allowing the flavors to meld and the beef to become tender.

Shred the beef: After 8 hours, carefully remove the beef to a rimmed baking sheet. Use two forks to shred the meat into bite-sized pieces.

Prepare the consome: Discard bay leaves and cinnamon stick from the crock pot. Using a high-powered blender or immersion blender, blend the remaining liquid until smooth. If using a standard blender, allow the liquid to cool slightly before blending in batches.

Store the sauce: Transfer the blended sauce back to the crock pot to keep warm. Add 1.5 to 2 cups of sauce to the shredded beef, tossing to coat thoroughly.

Prepare the tortillas: Dip doubled-up tortillas into the warm consome, soaking briefly. Then, lay them flat in a frying pan with a little avocado oil over medium heat.

Fill the tacos: On one half of each tortilla, layer cheese, followed by the shredded beef, diced onions, and cilantro leaves.

Fry the tacos: Cook for 2-3 minutes until the tortillas are crispy and the cheese is melting, then fold the tortilla over like a half moon.

Finish cooking: Ladle a small amount of consome on top of the tortilla. Flip and fry for an additional 2-3 minutes, ensuring both sides are golden and crunchy.