How to make / prepare - Potato Puff

2 cups mashed potatoes
2 tablespoons grated Parmesan cheese
1 tablespoon melted butter
2 tablespoons chopped onion
3 eggs, separated

Preheat oven to 350 degrees F.

Combine potatoes and Parmesan.
Add butter and onion.
Beat egg yolks and add them to the potato mixture.
Beat egg whites until they are stiff.
Fold egg whites into potato mixture.
Turn out into a deep, buttered 2-quart casserole.
Bake for 30 minutes or until a knife, inserted into the center, comes out clean.
Enjoy!