01 - In a small bowl, combine ground cumin, dried oregano, smoked paprika, sea salt, black pepper, and cinnamon. Mix thoroughly until evenly blended.
02 - Place the beef chuck chunks into the slow cooker. Sprinkle the spice blend over the meat and toss until every piece is evenly coated.
03 - Scatter the chopped onion, minced garlic, chopped chipotle peppers, and jalapeño over and around the seasoned beef in the slow cooker.
04 - In a separate bowl, whisk together the fresh lime juice, apple cider vinegar, beef broth, and tomato paste until smooth. Pour the liquid evenly over the beef and vegetables.
05 - Tuck the bay leaves into the liquid. Cover the slow cooker and cook on LOW for 8 hours, or until the beef is fork-tender and shreds apart effortlessly.
06 - Remove and discard the bay leaves. Using two forks, shred the beef directly in the slow cooker, mixing it thoroughly with the cooking juices to absorb maximum flavor.
07 - Serve hot in warm corn tortillas, burritos, or over rice, accompanied by fresh cilantro, diced onion, lime wedges, and your preferred toppings.