Step 1: Toast the peppercorns and coriander seeds in a dry skillet over medium heat until fragrant.
Step 2: Add the toasted spices, dried peppers, onion, garlic cloves, cinnamon stick, bay leaves, and remaining spices to a large pot.
Step 3: Cover with cold water and bring to a boil. Reduce heat to a simmer, cover, and cook for 15–20 minutes, or until the peppers are soft.
Step 4: Remove the cinnamon stick and bay leaves. Pour the remaining ingredients into a blender.
Step 5: Add some of the reserved cooking liquid to the blender.
Step 6: Add crushed tomatoes and blend until smooth. Set aside while you prepare the beef.
Part Two: Sear the Meat
Step 7: Cut the chuck roast into large chunks.
Step 8: Season the beef with kosher salt.
Step 9: In a heavy-bottomed skillet, heat oil over medium heat. Sear the chuck roast on all sides until browned, about 4–5 minutes per side.
Step 10: Remove the seared beef and place it into the crockpot.
Part Three: Finish in the Slow Cooker
Step 11: Pour the birria sauce over the chuck roast.
Step 12: Add beef broth.
Step 13: Season with salt and pepper to taste. Cook on High for 4 hours or Low for 8 hours, until the meat is tender.
Step 14: Transfer the cooked beef to a large bowl.
Part Four: Assemble the Sliders
Step 15: Shred the beef using forks (or your hands) and mix it back into the sauce.
Step 16: Place the bottom half of the slider buns in a baking dish or on a sheet pan. Evenly spread the shredded beef over the buns.
Step 17: Top with cheese.
Step 18: Drizzle with birria sauce.
Step 19: Brush the tops of the buns with consommé and place under the broiler until the cheese is melted.
Step 20: Remove from the oven and top with diced white onion and cilantro, if desired.
Step 21: Brush additional consommé over the tops of the sliders. Serve and enjoy.
Notes
Storage & Reheating
Refrigerate: Store leftover birria and consommé in an airtight container in the fridge for up to 4 days. Keep the meat and broth together to prevent drying out.
Freeze: Freeze birria (with some of the broth) in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator before reheating.
Reheat (Stovetop): Add birria and broth to a saucepan over medium heat and warm until heated through. Add extra broth if needed to keep the meat juicy.
Reheat Sliders: Wrap sliders in foil and warm in a 325°F oven until heated through. For best results, add a little extra consommé before reheating.