Cut the beef chuck roast into 3 chunks. Pat the meat dry with paper towel. Season evenly on all sides with the 3 teaspoons of salt and the 1 teaspoon of ground black pepper.
Heat about 2 tablespoons of olive oil on a large skillet over medium-high heat. Sear the beef on all sides, until nicely browned. Transfer the meat to a large slow cooker. Set aside. Tip: Searing the meat develops caramelization and browning, which adds so much flavor. The trick is letting the meat sear undisturbed for about 3-4 minutes per side, so that it can develop that beautiful golden brown crust. Prior to searing, make sure to pat the meat dry. Don't overcrowd the pan.
Make the marinade: In a food processor, combine the garlic cloves, chipotle peppers in adobo (including the juices), ground cumin, apple cider vinegar, and lime juice. Pulse to combine until you get a smooth and even marinade.
Pour the marinade over the beef in the slow cooker. To the slow cooker, add the beef broth, dried oregano, sliced onions, and bay leaves. Stir everything so that it’s combined (it doesn’t need to be perfect, just a few stirs to incorporate the ingredients).
Cover the slow cooker with the lid. Cook on LOW for 8 hours, or on HIGH for 4 hours.
Once the cooking time is up, shred the beef. If needed, season with more salt and pepper.
Serve over warm corn tortillas, and top with cilantro, diced onions, radishes...or any toppings you’d like! Serve with a few lime wedges. Enjoy!