Place the beef chuck roast in the slow cooker and add the sliced onion and minced garlic around it.
Pour the beef broth over the meat, then sprinkle the smoked paprika, salt, and black pepper on top.
Add the barbecue sauce, spreading it evenly to cover the roast.
Cover and cook on low for 8 hours until the beef is very tender.
Remove the beef from the slow cooker and shred it using two forks, discarding any large pieces of fat.
Return the shredded beef to the slow cooker and stir it into the remaining sauce until well coated.
Spoon the pulled beef onto the sandwich buns and serve.