Cut chuck roast into 2" - 3" cubes. Add 4C water to a large pot and then add roast, ¼ onion, and ½ head garlic. Boil over medium heat for 1 hour, occasionally skimming any fat off the top.

In a medium saucepan with a little vegetable oil, roast the guajillo, ancho, and arbol chiles along with the 3 garlic cloves over medium heat for 3 - 4 minutes.

Transfer roasted chiles and garlic to a blender and add peppercorns, cloves, 1 C water. Using tongs, pick up the ¼ onion and ½ head of garlic out of the meat pot. Squeeze garlic cloves out and add to the blender pot with the onion. Blend until smooth, then pass through a mesh strainer to remove sediment.

Add strained sauce into meat pot along with 1½ T salt, 2 bay leaves, ½ t oregano, ¼ t thyme, 1½ t cumin, and 1½ T beef bouillon. Reduce heat to low, cover pot and simmer for 2 hours. Remove meat and shred with 2 forks.

To assemble tacos, dip each corn tortilla in the beef consomme (from the meat pot), and fill ½ of the tortilla with the shredded meat and cheese. Fry in a medium skillet over medium high heat for a few minutes, then fold over half of the tortilla onto itself. Flip to brown the other side. Garnish with chopped cilantro, onions, and a small bowl of the beef consomme to dip in.