CHEESE AND MUSHROOM MANICOTTI

2 cups shredded Mozzarella cheese
2 cups shredded Cheddar cheese
1/4 pound mushrooms, coarsely chopped
2 ounces sliced ripe olives, drained
1/4 cup chopped onion
1/4 cup chopped celery
1/2 cup soft bread crumbs
1 egg, lightly beaten
1/4 cup milk
2 tablespoons chopped parsley
1/4 teaspoon pepper
4 cups prepared spaghetti sauce
1 cup water
8 manicotti shells
grated Parmesan cheese

In a large bowl, combine 1 cup of the Mozzarella with Cheddar cheese, mushrooms, olives, onion, celery, crumbs, egg, milk, parsley, and pepper; set aside. Combine spaghetti sauce and water; pour half the sauce into a shallow 3 quart casserole or baking dish. Stuff manicotti shells with cheese mixture and arrange side by side in sauce. Pour remaining sauce over top. Bake, covered, in a 375F degree oven for about 1 hour. Remove cover, sprinkle with remaining Mozzarella cheese, and return to oven, uncovered, for about 10 more minutes or until cheese is melted. Serve with Parmesan cheese.