1 lb. ground beef
1 lg. onion, chopped
1 clove garlic, chopped
8 oz. Mozzarella cheese, shredded
1/2 c. Italian style dry bread crumbs
Parmesan cheese
2 (4 oz.) cans mushrooms, pieces and stems
Salt and pepper
1 egg
2 jars (15 1/2 oz.) spaghetti sauce
18 giant shells

Brown ground beef, onion and garlic until beef is crumbly. Drain. Cool. Stir in cheese, crumbs and egg. Season to taste with salt and pepper. Cook shells in boiling salted water until tender, about 15 minutes. Drain. Use meat mixture to stuff shells. Spoon 1/4 of the sauce over the bottom of a 9 x 13-inch pan. Place shells on top of sauce and side by side. Pour remaining sauce over shells and sprinkle with Parmesan cheese and bake at 400 degrees for 25-30 minutes.