Preheat oven to 350 degrees F.
Combine potatoes and Parmesan. Add butter and onion. Beat egg yolks and
add them to the 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.
Recipe from Homeschoolforms.com, Site Maintained by Donna Young, of DonnaYoung.org