4 lg. yams, 4 lbs.
3 tbsp. sweet butter
1/2 c. heavy cream or milk
2 lg. egg yolks
2 lg. egg whites, room temp.
1 pinch cream of tartar

Bake yams on baking sheet 375 degrees 30 minutes. Prick, bake 30 more minutes until tender. Let cool. Skin yams, mash with fork and season with salt and pepper.

Heat butter and cream. Stir into yams. Stir in egg yolks.

Beat whites with pinch of salt until frothy. Add tartar and beat until stiff peaks. Fold whites into yam mixture and spoon into buttered 1 1/2 - 2 quart shallow baking dish. Smooth top and score lightly. 475 degrees, 15 or 2 minutes until puffed and browned slightly at edges. Serves 8.