Baked Spaghetti

1 cup onion, chopped
1 cup chopped green bell pepper
1 pound ground beef
1 (16 ounce) can diced tomatoes, with liquid
1 (8 ounce) can diced mushrooms, drained
1 teaspoon dried oregano
1 (12 ounce) package spaghetti, cooked and drained
2 cups shredded mild Cheddar cheese
1/4 cup water
1 (10.75 ounce) can cream of mushroom soup
1/4 cup grated Parmesan cheese

Preheat oven to 350 degrees F.

In a large skillet sauté the onion, green pepper, and ground beef. Once beef is brown and onion and pepper softened, add the tomatoes, mushrooms, and oregano. Simmer uncovered for 10 minutes.

Place half of the cooked spaghetti in a greased 9x13 inch pan. Top with half of meat mixture. Sprinkle with 1 cup of the mild cheddar cheese. Repeat. Mix cream of mushroom soup and water until smooth, pour over casserole.

Sprinkle with Parmesan cheese. Bake in the preheated oven for 30 to 35 minutes. Let stand 10 minutes before serving.