1/2 pound sweet Italian sausage
1 cup sliced mushrooms
1 cup green pepper slices, cut into 2-inch lengths
1/3 cup chopped onion
1/2 cup butter or margarine
1/3 cup unsifted all-purpose flour
2 1/4 cups milk
2 cups shredded Cheddar cheese
1/2 cup grated Parmesan or Romano cheese
1/2 teaspoon each salt and pepper
3 cups ziti, uncooked

Bake sausage at 350 degrees F for 30 minutes; cool.

Slice sausage in thin pieces; set aside. Saut