1 (9 inch) prepared graham cracker crust
1 (3 ounce) can sliced mushrooms
2 onions, chopped
2 eggs, beaten
1 cup evaporated milk
1 egg white, whisked
1 (8 ounce) container frozen whipped topping, thawed
1 (8 ounce) package cream cheese, softened
1 (8 ounce) container sour cream
1 (8 ounce) package shredded Swiss cheese
Preheat oven to 180 degrees F (80 degrees C).
From the carton of cream cheese: grease pie plate. Spoon the cream cheese mixture into pie shell. Cover the bottom and sides of pie. Shape filling into a single pie crust. Dust with powdered sugar if desired. Spread over cream cheese mixture.
When pie crust is fully baked, press whipping cream into filling. Place cream cheese mixture over pie filling to prevent burning.
Arrange mushrooms, onions and mushrooms in 2 or 3 layers on top of pie filling. Garnish with mushroom and onions and mushrooms, if desired.
In a large mixing bowl, beat cream cheese with eggs until fluffy. Mix in evaporated milk. Spread cream cheese mixture over cream cheese mixture. Place the Swiss cheese over cream cheese mixture to form a wedge shape. Spread a tablespoon of cream cheese over cream cheese mixture. Top with mushrooms and sliced green onions.
Bake in preheated oven for 35 minutes, or until internal temperature of pie reaches 140 degrees F (80 degrees C). Immediately remove pan from oven and let stand for 5 minutes. Pour sauce over pie. Cover and allow to cool completely.