Combine meat, 1/4 cup spaghetti sauce, and next 3 ingredients; stir well. Shape mixture into 48 (1-inch) meatballs. Place on a broiler pan coated with cooking spray. Broil 5 1/2 inches from heat (with electric oven door partially opened) 10 minutes or until done.
Coat a large nonstick skillet with cooking spray; place over medium-high heat until hot. Add red pepper and sliced onion; saute until tender. Add meatballs and remaining 1 3/4 cups spaghetti sauce; reduce heat, and cook, uncovered, 5 minutes, stirring often.
Cut a 1/4-inch-thick slice off top of each roll; set tops aside. Cut a 2-inch-wide, V-shaped wedge down length of each roll. Reserve bread wedges for another use. Place rolls and tops on a baking sheet; broil 5 1/2 inches from heat (with electric oven door partially opened) until lightly toasted.
Spoon meatball mixture evenly into bottom portions of toasted rolls; cover with roll tops. Serve warm.