Place the beef chunks in the slow cooker. Add the minced chipotle peppers, diced onion, and minced garlic on top.
Pour the beef broth over the meat and sprinkle in the cumin, smoked paprika, salt, and black pepper.
Cover and cook on low for 8 hours or on high for 4 to 5 hours until the beef shreds easily with two forks.
Shred the beef directly in the slow cooker and stir it into the juices to soak up the flavor.
Spoon the beef mixture into the center of each lettuce leaf. Top with avocado slices and a sprinkle of chopped cilantro.
Serve with lime wedges on the side for squeezing over the wraps just before eating.