Using gloves and scissors, remove the stems and seeds from the guajillo and ancho peppers, and place them in a small dish filled with boiling water. Submerge, and rest for 20 minutes.
2 Guajillo peppers, 2 Ancho peppers
Drain the soaked peppers, then place them in a food processor and blend until smoothed.
Slice the beef into chunks, then add them to a bowl and pour the blended peppers over top. Toss to coat the beef completely.
3 lbs Beef chuck roast
Add oil to a cast iron skillet and set it over medium-high heat. Once it's hot, add the beef chunks and sear until each side is well browned.
3 Tablespoons Olive oil
Once seared, transfer the beef to a slow cooker. De-glaze the cast iron pan with beef stock to gather up the browned bits, then add it to the slow cooker alongside all other barbacoa ingredients.
7 oz Chipotles in Adobo, 12 oz Beef stock, 4 Tablespoons Apple cider vinegar, 1 Lime, 1 Yellow onion, 3 cloves Garlic, 1 Tablespoon Oregano, 2 teaspoons Cumin, 3 Bay leaves, Salt and pepper
Cook on LOW for 6-8 hours, until the beef is tender and shreds easily. Shred the beef on a cutting board with two forks, then serve and enjoy!