Slow Cooker Monday - Stuffed Pasta Shells

18 jumbo pasta shells
1 lb. lean ground beef
1 onion, chopped
1 clove garlic, minced
2 cup Mozzarella cheese, shredded
1/2 cup seasoned bread crumbs
1 tbsp. parsley flakes
1 egg, beaten
2 jars meatless spaghetti sauce (151/2 oz. each)
1/2 cup grated Parmesan cheese

Cook pasta shells according to directions, just until tender and drain. Meanwhile, brown beef, onion and garlic on stove top, drain. Add Mozzarella, bread crumbs, parsley and egg. Stuff shells, set aside. Pour 1 jar of sauce into slow cooker. Arrange stuffed shells in sauce. Top with other jar of sauce and Parmesan cheese. Cover and cook on low 5 to 7 hours.