First, toast the dried guajillo and ancho chilies in a dry skillet over medium heat for about 30 seconds per side until they become fragrant. Be careful not to burn them. Transfer the toasted chilies to a bowl, cover them with hot water, and let them soak for about 10 minutes to soften. Meanwhile, season the beef generously with salt. Heat the oil in your Dutch oven over medium-high heat and sear the beef on all sides until a deep brown crust forms. Remove the meat and set it aside.
Drain the softened chilies and add them to a blender. Also add the chipotle pepper, chopped onion, garlic cloves, cumin, cinnamon, cloves, oregano, and one cup of the beef broth. Blend everything on high speed until the mixture is completely smooth. This vibrant red sauce is the heart of the birria's flavor, so ensure it is well-blended.
Return the seared beef to the Dutch oven. Pour the blended chili sauce over the meat, then add the remaining beef broth and the bay leaves. Bring the mixture to a simmer, then reduce the heat to low, cover the pot, and let it cook for 2.5 to 3 hours. The meat is ready when it is fork-tender and falls apart easily. Once cooked, remove the meat from the pot and shred it using two forks. Reserve the remaining cooking liquid, also known as the consommé.
Preheat your oven to 375°F (190°C). Prepare the tortillas by lightly dipping each one into the warm birria consommé. This step is crucial as it softens the tortillas and infuses them with flavor. Warm each dipped tortilla on a hot skillet for a few seconds per side. Spoon a generous amount of the shredded birria meat onto each tortilla, add a sprinkle of cheese and some diced onion if you're using it, then roll them up and place them seam-side down in your baking dish.
Once all the enchiladas are arranged in the baking dish, pour a little more of the reserved consommé over the top. This keeps them moist and adds more flavor. Sprinkle the remaining shredded cheese generously over all the enchiladas. Bake them uncovered for 15-20 minutes, or until the cheese is completely melted, bubbly, and just beginning to turn golden brown at the edges.