8 oz pkg Manicotti Shells
1 lb Ground Beef
1/2 cup chopped Onion
26 oz jar Spaghetti Sauce
14 pieces Mozzarella String Cheese
1 1/2 cups shredded Mozzarella
Cook Manicotti according to package directions. Meanwhile, in a large skillet, cook beef and onion over medium heat until no longer pink. Stir in spaghetti sauce. Spread half of the sauce into a 9 x 13 baking dish. Drain manicotti and stuff each shell with a piece of string cheese. Place over meat sauce, top with remaining meat sauce. Cover and bake at 350 degrees for 25 to 30 minutes or until heated through. Sprinkle with mozzarella cheese. Bake, uncovered for 5 to 10 minutes or until cheese is melted.