01 - Combine kosher salt, black pepper, smoked paprika, garlic powder, onion powder, and ground cumin in a small bowl. Rub the mixture evenly over the beef chuck roast.
02 - Place sliced onion and minced garlic in the bottom of the slow cooker. Lay the seasoned beef roast atop the aromatics.
03 - Whisk together beef broth, barbecue sauce, apple cider vinegar, and Worcestershire sauce. Pour the mixture evenly over the beef in the slow cooker.
04 - Cover and cook on LOW heat setting for 8 hours, or until the beef is fork-tender and shreds effortlessly.
05 - Remove the beef and shred it using two forks. Skim excess fat from the cooking liquid, return shredded beef to the slow cooker, and stir to coat with the juices.
06 - Toast sandwich buns if desired. Pile the pulled beef onto each bun and top with extra barbecue sauce, coleslaw, and pickles as preferred. Serve immediately.