Season the pork shoulder with the BBQ seasoning.
Salt and pepper the pork shoulder to taste.
Place the onion in the bottom of the slow cooker.
Rest the pork on top of the onion.
Cook on low for 6-8 hours.
Use two forks to shred the pork.
Stir in 2 cups of bbq sauce and cook an additional 30 minutes on low.
Serve as sandwiches with coleslaw