Place the pork roast in the crock pot with chicken broth, salt, and pepper. Cover and cook on low 8 hours. I don't recommend cooking on high. When it is done cooking, remove the roast and shred with 2 forks and stir in enough bbq sauce to coat all the meat. You can also moisten the meat with a little of the cooking juices, I usually use about 1/2 cup.
Warm your flatbread a little then top with bbq pork, coleslaw, lettuce, tomato and onion. Serve immediately.
Leftover meat can be stored in the refrigerator for up to 6 days.