I've adapted this from a recipe from my good friend Erik Black. Credit really goes to him.
1 boston butt (really pork shoulder, but I like the sound of boston butt better) ~2 pounds
1/2 diced onion
1/3 cup apple vinneger
2 tblspoons olive oil
2 tblspoons worcheschire sauce.
2 tblespoons brown mustard
Brown sugar to cover.
Preheat oven to 250. Place the butt in either a roasting pan or cast iron skillit. Sprinkle salt and pepper on top. Rub on a thin coating of brown sugar over the butt. Mix the vinneger, olive oil, and brown mustard together and pour over butt. Toss in the onions. A good general rule for time is 2 hours for every butt pound. If ya want, toss it on the grill for 30 min to char before putting it in the oven. Be sure to save the juices though. Once pulled the pulled bits will easily (and deliciously) soak them up. The taste is a nice ballance between the tartness of a North Carolina pulled pork, and the sweeter bbq sauces you'll find at the store.