01 - In a small bowl, thoroughly combine all the ingredients for the dry rub.
02 - Pat the beef chuck roast dry with paper towels. Rub the entire surface of the beef with olive oil, then generously coat it with the prepared dry rub.
03 - Carefully place the seasoned beef roast into the slow cooker.
04 - In a separate bowl, whisk together the beef broth, Worcestershire sauce, apple cider vinegar, brown sugar, and tomato paste until well combined. Pour this mixture over the beef in the slow cooker.
05 - Cover the slow cooker and cook on the LOW setting for 8 hours, or until the beef is exceptionally tender and can be easily shredded with a fork.
06 - Once cooked, transfer the tender beef to a large bowl. Using two forks, shred the beef into fine strands. Skim any excess fat from the liquid remaining in the slow cooker, then return some of this cooking liquid to the shredded meat until your desired level of juiciness is achieved.
07 - Lightly toast the sandwich buns if a crispy texture is desired.
08 - Pile the warm, shredded pulled beef onto the prepared buns. Top generously with homemade coleslaw and add pickles if you are using them. Serve immediately.