1. Preheat oven to 400°F. Heat large nonstick skillet over medium heat until hot. Add Ground Beef; cook 8 to 10 minutes, breaking beef into small crumbles, stirring occasionally. Add pasta sauce, onion, bell pepper, Italian seasoning and salt; continue cooking 5 minutes or until vegetables are crisp-tender, stirring occasionally.
2. Top each muffin half evenly with beef mixture and cheeses. Bake at 400°F 5 to 7 minutes or until cheese is melted.
Test Kitchen Tips Cooking times are for fresh or thoroughly thawed Ground Beef. Ground Beef should be cooked to an internal temperature of 160ºF. Color is not a reliable indicator of Ground Beef doneness.