01 - Toast the dried guajillo, ancho, and pasilla chiles in a dry skillet over medium heat for 2 to 3 minutes until fragrant. Transfer to a bowl, cover with hot water, and let soften for 10 minutes.
02 - Combine the softened chiles, onion, garlic, tomatoes, cumin, oregano, thyme, paprika, cinnamon stick, cloves, bay leaves, peppercorns, apple cider vinegar, and 1 cup of beef broth in a blender. Blend until completely smooth.
03 - Add the beef chuck chunks and short ribs to the slow cooker. Pour the blended sauce over the meat. Add the remaining beef broth and salt, then stir to coat the meat evenly.
04 - Cover and cook on low for 8 hours, or until the meat is fork-tender and easily pulls apart.
05 - Remove the beef from the slow cooker and shred with two forks. Discard the bones. Skim excess fat from the surface of the cooking liquid, then strain the consommé through a fine-mesh sieve and reserve for dipping.
06 - Heat a skillet over medium heat. Lightly dip each corn tortilla in the fat from the consommé, then place in the skillet. Top with shredded beef and cheese if desired. Fold and cook until crispy and golden on both sides.
07 - Serve the tacos topped with diced white onion, chopped cilantro, and lime wedges, with a cup of warm consommé alongside for dipping.