Place the roast in the slow cooker and add the tomatoes, onion, garlic, salt and bay leaves, then pour water over the roast. Place the lid on and set on high for 6 hours or low for 8.
After the meat has been cooking for 4 hours (if cooking on high) to 6 hours (if cooking on low), make the sauce.
Using gloves and scissors, cut the chiles open and remove the stem and seeds. Place them in a bowl and cover with boiling hot water. Let them soak for 20 minutes. You may need to place a small plate or bowl on them to weigh them down and keep them under the water.
Place the spices in a pan over medium high heat and toast for 1 to 2 minutes, or until you can begin to smell the spices. Stir often. Pour the spices into a blender.
Place the garlic in the same pan and brown each side, then pour into the blender.
Spoon out 2 cups of the beef broth from the crockpot, and the tomatoes, and add to the blender. Drain the chilis and add them to the blender as well, then blend until smooth.
Add the vinegar, and a teaspoon of salt, and blend for 10 seconds more.
Pour the chile sauce mixture through a fine mesh strainer and press with a spoon until strained.
When the meat is tender, remove from the broth and shred. Discard garlic head from crockpot.
Add the sauce to the slow cooker and stir into the broth. Add the meat back into the slow cooker and continue cooking for another hour.
Serve with your favorite toppings, as Birria Tacos, in enchiladas, quesadillas or burritos!
Less Spicy: Reduce the amount of Dried Arbol Chiles if you’re not a fan of heat.Chuck Roast: If you can’t find a good chuck roast, you can also use beef shank, boneless beef short ribs, or beef cheeks. You want a fatty cut of beef to give your birria good flavor.Leave The Fat: Don’t cut the fat off the meat. Use the cooking grease to fry tortillas for birria tacos or enchiladas.Thicken The Sauce: If the sauce hasn’t thickened when the meat is ready, you can pour it off and simmer it in a pan over medium heat for about 10 to 15 minutes.Storage:When the crockpot birria comes down to room temperature, refrigerate it in an airtight container for up to 5 days. To reheat it, microwave it for up to a minute or until warm. You can also heat it in a pan or small pot over medium heat for 6-8 minutes.Freeze: Once fully cooled, transfer it to a freezer-friendly bag or container in serving-size portions. Freeze for up to 3 months. Thaw it overnight in the fridge before reheating as usual.