In a large pot, add the chuck roast, short ribs, halved onion, garlic bulb, carrot, bay leaves, and guajillo chiles. Pour in hot water until everything is submerged. Bring to a boil over medium heat.

Once boiling, stir in the chicken bouillon, oregano, cumin, and salt to taste. Ensure it doesn't boil too vigorously to avoid toughening the meat.

After 30 minutes, skim off any impurities that rise to the surface for a clearer broth.

Blend the softened guajillo chiles, onion, garlic, and carrot in a blender until smooth, adding some broth if necessary for consistency.

Strain the blended mixture back into the pot, discarding solids.

Season the broth with chili powder to taste and simmer for about 3 hours on low heat until the meat is tender.

Once cooked, remove the meat and shred it using two forks, retaining some texture.

Skim off grease from the broth, reserving it for frying the tortillas.

Heat the tortillas in the reserved grease over medium heat until warm and slightly crispy.

Fill each tortilla with shredded meat, diced onions, cilantro, and a squeeze of fresh lime juice.