Preheat oven to 400 degrees. Add cooked shredded pork to a baking dish and cover with tin foil. Bake for 15 minutes as you prepare the other ingredients.
For the slaw:
Add cabbages and carrot to a large bowl.
Add remaining ingredients to a mason jar and shake to combine. Pour over cabbage and carrot mixture, tossing to coat completely.
To serve:
Remove pork from the oven and add barbecue sauce. Mix completely to combine. Add barbecue pork to the bottoms of buns and top with coleslaw. Serve with pickles and pickled red onions.