Dice onion, celery, carrots and garlic. Sprinkle with salt then roast for 5 minutes.
Add half of diced vegetables to slow cooker with 1 tablespoon of ghee or butter. Mix well.
Place chuck roast in the slow cooker then top with remaining vegetables. Pour ¾ cup of BBQ sauce and ½ cup water into slow cooker. Close and cook on low for eight hours.
Open slow cooker and carefully remove beef with tongs. Place in large bowl and use forks to shred.
Add remaining BBQ sauce and gently toss to combine. Serve with mashed sweet potatoes.
