Combine kosher salt, black pepper and paprika. Coat pork butt evenly with mixture, shaking off any excess. Soak 2 cups hickory wood chips and
1 cup apple wood chips in water 30 minutes.
Place pork butt in smoker on rack at 220 degrees F for 8 hours, with smoke going for 2 hours. Let cool slightly. Break meat apart with hands.
Saute onions in oil in heavy saucepan until translucent. Add spices and cook until fragrant. Add remaining ingredients and cook until mixture is thick and coats back of spoon. Puree sauce and let cool. (Sauce can be made 2 to 3 days in advance and refrigerated.).
Combine pork and sauce (to taste) in heavy saucepan. Cook until heated through. Pile pork on roll.