Put the guajillo and ancho chilies in a pot and cover with water. Bring to a boil then remove the pot from heat and cover. Let chilies soak for 30 min.

Heat up a pan over medium heat. Add the onion, garlic and tomatoes. Cook until roasted with blackened spots. The garlic should be done after 5 min or so. The tomatoes and onion will take longer. Make sure to turn for even cooking.

Transfer the onion and tomatoes to the blender along with the peeled garlic cloves.

Then add the soaked chilies to the blender but not the soaking water. Also add the vinegar, oregano, thyme, cumin, cloves, cinnamon, peppercorns, chicken bouillon and 2 cups of fresh water to the blender. Blend until smooth and set aside.

Season the meat with salt. Heat up a large pot over medium heat. In batches brown the meat on all sides until a golden crust forms.

Turn the heat to medium low. Strain the blended sauce into the pot. Stir the bottom of the pot well to scrape up any browned bits. Cook for 1 min.

Return the meat to the pot. Add the remaining 9 cups of water and bay leaves. Stir. Bring to a boil. Reduce heat to low and cover. Cook for 3 hours or until the meat is tender.

Transfer the meat to a large bowl and shred with a fork. Discard any pieces of fat. Return half of the shredded meat to the pot. Use the other half to make quesatacos if desired!