Baked Spaghetti with Cream of Mushroom Soup

Preheat your oven to 350°F. In a large skillet, saute the onion and green pepper in the butter until tender. Add the tomatoes, mushrooms, olives, oregano and, if desired, the ground beef. Simmer them, uncovered, for 10 minutes.

Place half of the spaghetti in a greased 13x9-inch baking dish. Layer this with half of the vegetable mixture and 1 cup of the cheddar cheese. Repeat this step to make layers.

In a small bowl, combine the mushroom soup and water until they're smooth, then pour the mixture over the casserole. Sprinkle the casserole with the Parmesan cheese. Bake it, uncovered, until it's heated through, about 30 to 35 minutes. Let it cool for a few minutes at room temperature, then serve it.