Season the beef: Pat the beef dry with paper towels. Season all sides with kosher salt and black pepper.
4 lbs. boneless beef chuck roast, 1½ tsp. kosher salt, 1/2 tsp. black pepper
Sear: Heat vegetable oil in a large skillet over medium-high heat. Working in batches if needed, sear beef on all sides until browned (about 2-3 minutes per side). Transfer seared beef to the slow cooker. Start Timer
1-2 Tbsp. vegetable oil
Make the sauce: In a blender, combine the sauce ingredients (except bay leaves) and blend until smooth.
2-3 chipotle peppers in adobo, 1 Tbsp. adobo sauce, 1 cup beef broth, 1/2 white onion, 2 Tbsp. apple cider vinegar, Juice of 2 limes, 4-6 cloves garlic, 1 Tbsp. kosher salt, 2 tsp. ground cumin, 1 tsp. Mexican oregano, 1/2 tsp ground cloves
Add to slow cooker: Pour the blended sauce over the slow cooker. Now add the bay leaves. Cover and cook on low for 8-10 hours, until the beef is fork-tender and shreds easily. I really recommend a low and slow for this, as opposed to High for a shorter time. Start Timer
2 bay leaves
Shred: Remove bay leaves and discard. Shred the beef directly in the slow cooker and stir in the sauce.
Serve: Serve with warm corn tortillas, diced white onion, fresh cilantro, lime wedges, Cotija cheese, pickles red onions, etc. Can be made into tacos, burrito bowls, served over nachos, quesadillas, breakfast tacos, burritos, etc.