Walleye in Creamy Orange Sauce

2 tablespoons margarine or butter 

2 tablespoons finely chopped onion 

1 tablespoon all-purpose flour

2 teaspoons grated orange peel 

1/4 teaspoon salt

1/8 teaspoon pepper

1 cup milk

4-6 walleye fillets (1 1/2 - 2 lbs)

Heat oven to 300. Grease 13 x 9-inch baking pan. In small saucepan, melt margarine over medium heat. Stir in onion and cook until translucent.  Stir in orange peel, salt and pepper.  Stir in flour.  Blend in milk. Cook over medium heat, stirring constantly, until thickened and bubbly, about 4 minutes. Set aside.

Cut fish into serving-size pieces. Place in prepared pan. Pour sauce over fish. Cover with foil. Bake until fish flakes easily at thickest part, about 25-30 minutes. Garnish with orange slices, if desired.