1 1/2 c. uncooked elbow macaroni
1 medium onion, peeled and chopped
1 Tbsp. margarine
2 Tbsp. flour
1/4 tsp. pepper
1/4 tsp. oregano
2 c. skim milk
1 c. (4 oz.) shredded low-fat Swiss cheese
1 c. (4 oz.) shredded low-fat Cheddar cheese
1/4 c. chopped fresh parsley
1 medium tomato, chopped (optional)

Cook elbow macaroni according to package directions, omitting oil and salt; drain. Rinse macaroni under cold running water and drain again. Set macaroni aside.

Sauté onion in margarine in a medium saucepan until tender. Add flour, pepper and oregano, stirring until smooth. Cook one minute, stirring constantly. Gradually add milk; cook mixture over medium heat until thin white sauce. Stir in Swiss and Cheddar cheeses; reduce heat and cook until cheeses melt. Remove from heat; stir in macaroni, parsley and tomato. Bake in 1 1/2 quart casserole at 350° for 30 minutes. Yields eight 3/4-cup servings.