Slow Cooker BBQ Beef Sandwiches

Chuck roast needs time to soften, so let a fork decide when it is ready. Save some of the cooking juices before adding the barbecue sauce; a splash keeps the shredded beef moist without making the sandwiches soupy. Add the coleslaw when you build the sandwiches.
Homemade sauce: HKT BBQ Sauce — https://www.homegrownkitchentable.com/all-recipes/how-to-make-your-own-bbq-sauce
Ingredients
2½–3 pounds boneless beef chuck roast, fully thawed
Up to 1 teaspoon salt, added only after tasting the finished sauce
1 teaspoon black pepper
¼ teaspoon garlic powder
½ teaspoon onion powder
½ teaspoon chili powder
1 teaspoon smoked paprika
2 cups prepared HKT BBQ Sauce
6 sandwich buns, split
Prepared coleslaw, for serving
Instructions
Trim away any large hard pieces of surface fat, leaving the softer seams within the chuck roast. Stir the pepper, garlic powder, onion powder, chili powder and smoked paprika together. Rub the mixture over all sides of the fully thawed beef.
Put the roast in a 4–6-quart slow cooker and cover. Cook on LOW for about 8–10 hours, until the meat pulls apart easily with two forks. Begin checking around 8 hours. Chuck can be cooked through before it is tender enough to shred; cover it again and give it more time if it is still firm. The roast will release its own cooking juices.
Transfer the tender beef to a rimmed board or dish. Pour the cooker juices into a heatproof bowl and let the fat rise, then skim it off. Save the defatted juices. Shred the beef, removing tough connective pieces and any large pockets of fat, and return the meat to the cooker.
Warm the measured 2 cups barbecue sauce in a saucepan until steaming, stirring to prevent scorching. Stir all of it into the shredded beef, then add a small splash of the saved defatted cooking juices only if the meat needs moisture. Cover and heat on LOW for about 15–30 minutes until hot throughout. Use only enough juices for a moist coating; leave the extra out so the buns do not become soggy. Taste the fully cooked beef with its sauce before adding any of the optional salt; add a little at a time, up to the listed 1 teaspoon, only if needed.
Divide the sauced beef among the 6 split buns. Spoon coleslaw onto each sandwich just before serving, or serve it on the side. Keep the slaw separate from the hot beef until you are ready to eat.
Refrigerate leftover beef in shallow containers within 2 hours, or within 1 hour above 90°F, and use within 3–4 days. Reheat to 165°F throughout. For freezing, package the cooked beef with its sauce in meal-size freezer containers and freeze for up to 3 months for best quality. Thaw in the refrigerator, then reheat to 165°F in a covered saucepan or microwave-safe dish; do not use the slow cooker to reheat cold leftovers. Freeze the buns separately and make fresh coleslaw for serving.