01 - Rub the beef chuck roast thoroughly with kosher salt and freshly ground black pepper on all sides for even flavor distribution.
02 - Heat olive oil in a large skillet over medium-high heat. Sear the seasoned beef on all sides until a deep brown crust forms, approximately 3-4 minutes per side.
03 - Place the seared beef into the slow cooker insert, ensuring it sits flat for even cooking.
04 - Whisk together the barbecue sauce, beef broth, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, and cayenne pepper until fully combined.
05 - Pour the prepared sauce mixture evenly over the beef in the slow cooker.
06 - Cover and cook on low setting for 8 hours or on high for 4 hours until the beef pulls apart easily with minimal resistance.
07 - Remove the cooked beef from the slow cooker and shred using two forks. Skim any excess fat from the cooking liquid, then return the shredded beef to the sauce and toss to coat thoroughly.
08 - Brush the cut sides of the sandwich buns with melted butter and toast in a skillet or under the broiler until golden brown and crispy.
09 - Generously pile the sauced pulled beef onto the toasted buns. Top with coleslaw if desired and serve immediately while warm.