Brown:

1 lb. ground beef
1/4 c. chopped onion (1 sm. onion)

Drain off fat. Add 15 ounce jar spaghetti sauce with mushrooms. Simmer 10 minutes. Break 8 ounce spaghetti in quarters and cook according to directions on package. Rinse and drain. Mix spaghetti and sauce.

Melt 2 tablespoons butter in saucepan; stir in 1 tablespoon flour and 1/4 teaspoon salt. Add 3/4 cup undiluted evaporated milk and 1/2 cup water. Cook over medium heat until slightly thickened; stir constantly. Add 1 cup shredded cheese and 3 tablespoons grated Parmesan cheese; stir until melted.

Spread 1/2 the spaghetti mixture in 10 x 6 x 2 inch baking dish. Top with all of cheese sauce. Add rest of the spaghetti mixture and top with grated cheese. Bake at 350 degrees for 20 minutes.