Start by seasoning your beef chuck roast generously with salt and pepper. Heat oil in a skillet and sear the meat on all sides until browned. This step locks in flavor and gives the final dish a deep, savory base.
Transfer the seared beef to your slow cooker. Add guajillo chiles, chipotle chiles, onion, garlic, beef stock, tomato paste, diced tomatoes, vinegar, and all the spices (including cinnamon stick and bay leaves). Stir gently, cover, and cook on low for 8 hours. By the end, the beef will be fall-apart tender.
Once the beef is cooked, remove it from the slow cooker and shred it with two forks. Discard the bay leaves and cinnamon stick. Use an immersion blender (or transfer to a blender in batches) to puree the remaining liquid into a smooth, rich consomé. Add a few ladles of this sauce to the shredded beef to keep it juicy.
Dip each tortilla into the consomé so it’s coated in that beautiful red sauce. Lay it on a hot skillet, sprinkle with cheese, add shredded beef, onion, and cilantro, then fold it over. Fry each side until golden and crispy. Repeat for the rest, and serve with small bowls of the consomé for dipping.