Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   4      6 oz          trout or salmon fillets
                        -----egg sauce-----
     1/4  teaspoon      dry mustard
     1/4  teaspoon      salt
   2      cups          milk
   1                    hard-boiled egg -- chopped
   2      tablespoons   butter
   2      tablespoons   flour
   1      tablespoon    chopped parsley
                        few grains pepper

Preparation:

Place fillets on a greased rack and steam over salted water until fish is cooked, about 10 minutes or less. Remove from the heat and keep warm. Discard the liquid. In a saucepan combine melted butter, flour, mustard, 1/4 teaspoon salt and the pepper. Stir in 1 cup hot milk. Cook and stir over moderate heat until smoothly thickened. Add egg and parsley; mix well. Pour sauce over fish and reheat for several minutes. Adapted from a recipe in "Froze Fillets", Department of Fisheries and Oceans Canada