Mashed Potato Souffle - cooking recipe

Ingredients

4 lb. Idaho potatoes, mashed
1/2 c. heavy cream
1/4 c. grated onion
8 slices large sweet onion
1 tsp. salt
1 stick (1/2 c.) softened salted butter
2 egg yolks
4 egg whites
salt and white pepper
cream of tartar

Preparation

In a large bowl combine mashed potatoes, heavy cream, onion and 1 teaspoon salt.
Into the potato mixture, beat in the stick of softened butter, 2 egg yolks and salt and white pepper to taste.
In another bowl beat the 4 egg whites with a pinch of salt and cream of tartar until stiff peaks form.
Fold this into the potato mixture.
Put the souffle into a buttered 1 to 1 1/2-quart casserole.
Top it with the onion slices, brush it with butter and bake it for 45 minutes.
Serves 8.
This recipe should not be doubled.