Creating Authentic Mexican Birria may seem intimidating, but these step-by-step instructions will guide you through the process seamlessly:

1. Prepare the Chiles: In a dry skillet, toast the guajillo, ancho, and pasilla chiles over medium heat until fragrant, about 2-3 minutes. Don’t let them burn.
2. Soak the Chiles: Place the toasted chiles in a bowl of hot water. Allow them to soak for 15-20 minutes until softened.
3. Make the Marinade: In a blender, combine the softened chiles, chopped onion, minced garlic, cumin, oregano, black pepper, and salt. Blend until you get a smooth paste.
4. Prep the Meat: Cut the meat into large chunks and place it in a large bowl. Pour the marinade over the meat, ensuring it’s well-coated. Let it marinate for at least 1 hour; overnight is preferable for deeper flavor.
5. Sear the Meat: In a large pot or Dutch oven, heat a little oil over medium-high heat. Add the marinated meat and sear until browned on all sides, about 10 minutes.
6. Add Broth and Seasoning: Pour the broth into the pot and add the bay leaves and vinegar. Bring to a simmer.
7. Cook the Birria: Cover the pot and reduce the heat to low. Allow it to cook for about 3 hours or until the meat is tender and falls apart easily.
8. Shred the Meat: Once cooked, remove the meat from the pot. Shred it using two forks and set aside.
9. Finalize the Broth: Strain the broth to remove any solids, if desired. Return the liquid to the pot and incorporate the shredded meat back into the broth.
10. Serve: Allow the dish to rest for 30 minutes before serving, giving time for the flavors to meld.

Following these steps will help you create an authentic dish that honors traditional Mexican culinary practices.