2 Maine lobsters (1¼ lbs.), cooked
1 cup mushrooms, sliced
¼ cup onion, chopped
2 tablespoons butter
3 tablespoons flour
¼ teaspoon salt
1 dash pepper
1 cup milk
1 egg yolk, slightly beaten
4 ounces Swiss cheese, shredded
Remove Maine Lobster meat from shells and cut into bite sized pieces, set aside.
In a sauce pan, cook mushrooms and onion in the butter, stir in flour, salt and pepper. Add the milk all at once and cook, stirring constantly until thickened and bubbly. Stir about half of the hot mixture into the beaten egg yolk, and then return all to the saucepan. Cook and stir for one minute more, remove from heat. Fold Maine Lobster meat into the sauce.
Lightly grease a medium casserole dish and spoon the mixture into dish. Sprinkle with the Swiss cheese and broil 6 or 7 inches from the heat until warmed and cheese is lightly browned, approximately 8 minutes.