FLOUNDER AU GRATIN

1 tb Margarine
4 Green Onions Cut Into 1/2 Inch Pieces
2 tb Diced Celery
2 tsp Flour
1/8 tsp Salt
1/8 tsp White Pepper
1/2 c Skim Milk
1/4 c (1 Oz.) Shredded Swiss Cheese
1 (16 Oz.) Package Frozen Flounder, Thawed & Drained
1 tb Minced Fresh Parsley

Melt margarine in a small saucepan over low heat. Add onions & celery; saute until tender. Stir in flour, salt & pepper; cook 1 min. stirring constantly. Gradually add milk; stir well. Cook over medium heat until thickened & bubbly, stirring constantly. Add shredded Swiss Cheese; reduce heat & cook until cheese melts, stirring constantly. Set aside. Arrange fillets in a single layer in a 10 X 6 X 2 inch, baking dish coated with cooking spray. Pour cheese mixture evenly over fillets. Cover & bake at 350 for 25 min. OR until fillets flake easily when tested with a fork. Sprinkle with parsley.