1/2 lb. elbow macaroni
4 tbsp. butter
3 tbsp. all-purpose flour
1 tsp. salt
1/2 tsp. white pepper
1 tbsp. grated onion
2 eggs
2 c. milk
1 c. shredded sharp cheddar cheese
1 c. Velveeta cheese
1/2 c. grated Parmesan cheese
1 (4 oz.) can button mushrooms, drained
1/2 c. finely chopped celery
1/4 c. chopped green pepper
Pimiento strips for garnish

Cook macaroni in boiling salted water until tender, about 8 to 10 minutes; drain and rinse.

Melt butter in saucepan. Stir in flour, salt and pepper and onion. Mix eggs with milk and blend thoroughly. Stir into butter mixture and cook over low heat, stirring constantly until thickened. Add cheese, stir until blended. Fold in cooked macaroni, mushrooms, celery and green peppers. Pour macaroni in buttered 2 quart casserole and bake in preheated 350 degree oven for 25 to 30 minutes. Garnish with strips of pimiento if desired.