Remove casing from chorizo (if using). In a large skillet cook sausage and ground turkey or beef, half at a time, until meat is cooked through. Drain off fat. In a 5- or 6-quart crockery cooker combine onion, tomato sauce, undrained tomatoes, tapioca, jalapeno peppers, sugar, and oregano. Stir in the meat.
Cover; cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours. Using a fork, hollow out bottom halves of rolls, leaving a 1/4-inch-thick shell. Spoon meat mixture into roll bottoms. Add roll tops. If desired, serve with sliced olives, shredded cheese, and/or cherry peppers. Makes 16 servings.