Pork shoulder/butt roast, whatever size you want
1/2 cup brown sugar
1/2 cup paprika
1/4 cup salt
1/4 cup chili powder
1/4 cup dry mustard
1/4 cup garlic powder
1/4 onion powder
3 tablespoon black pepper
He often throws some baking cocoa in there too, maybe just 1/8 cup or less
Mix all that together, after cutting off the fat rub the whole thing with the rub and put it in the fridge overnight. Cook on 225 for 10 hours, when it comes out let it sit, still covered for about 15 minutes before you mess with it. He said the key is when you put it in the oven to have it completely covered and sealed in tin foil so no air can escape.