1 (12 oz.) pkg. thin spaghetti
1/4 lb. bacon, cut in small pieces
1 med. onion, chopped
1 lb. ground beef
2 (8 oz.) cans tomato sauce
1 (4 oz.) can sliced mushrooms, drained
1 1/2 tsp. salt
1/4 tsp. oregano
1/2 tsp. garlic salt
1 c. grated Cheddar cheese
1 c. grated Provolone cheese

Cook spaghetti according to package directions. Drain and set aside. Meanwhile, fry bacon until brown. Drain off excess fat. Add onion and seasonings. Simmer 15 minutes.

In a large bowl, combine sauce and spaghetti. Place half of mixture in a buttered 2 quart casserole. Top with half the Cheddar and half the Provolone cheese. Repeat layers. Bake covered at 375 degrees for 20 to 25 minutes.