4 lg. yams (about 4 lb.)
3 tbsp. butter
1/2 c. milk or cream
2 lg. egg yolks
2 lg. egg whites, room temperature
Pinch of tartar

Bake yams on a baking sheet in 375 degree oven for 30 minutes, prick with fork and bake for 30 minutes more or until tender. Let cool until they can be handled and scrape flesh into a bowl, discard skins. Mash and season with salt and pepper.

In saucepan, heat butter and cream over moderately low heat until butter is melted. Stir in yams and egg yolks.

Beat egg whites with pinch of salt until frothy. Add cream of tartar and beat until stiff peaks. Fold whites into yam mix and spoon into buttered 1 1/2 to 2 quart shallow baking dish. Bake at 475 degrees for 15-20 minutes until puffed and brown around edges. Serves 8. (Can be made the day before and baked before the dinner.)