1. Combine egg, and the 1/4 cup spaghetti sauce in a large mixing bowl. Stir in bread crumbs, onion, basil or oregano, and garlic. Add beef and sausage; mix well. Shape meat mixture into eight 1/2-inch-thick patties.
2. Tear off a 12x18-inch piece of heavy foil. Place pepper slices in center of foil; drizzle with oil. Bring up 2 opposite edges of foil;seal with a double fold. Then fold in remaining ends to enclose the peppers, leaving place for steam to build.
3. Grill burgers and foil packet on the rack of an uncovered grill directly over medium coals for 10 to 12 minutes or until burgers are no longer pink and peppers are tender, turning burgers and foil packet once halfway through grilling time.
4. Top each burger with some of the pepper strips and a half slice of cheese; cover and grill about 15 seconds more or until cheese melts.
5. Meanwhile, heat the 1 cup of spaghetti sauce either on the grill or stove top. To serve, place burgers on kaiser rolls. Spoon spaghetti sauce over burgers. Pass any remaining sauce.