Yam and Applesauce Souffle

4 large yams or sweet potatoes (3 cups worth)
5 tablespoons non-hydrogenated vegetable shortening (Earth Balance)
½ teaspoon salt
½ teaspoon grated lemon zest
2 eggs, separated
¾ cup unsweetened applesauce
2 or 3 teaspoons pure maple syrup (to taste)

Peel the sweet potatoes or yams, cut in slices, and put them in a saucepan with enough water to cover. Boil until tender, about 15-20 minutes. Drain and place in a large bowl. Mash the potatoes with the shortening, salt, lemon zest, and beaten egg yolks. Stir in the applesauce. Season to taste with maple syrup; (you may need more or less, depending upon the sweetness of the yams). Cool slightly. Beat the egg whites until stiff. Stir a little bit of the egg whites into the yam mixture to loosen it a bit; then fold in all of the egg whites. Pour into an oiled casserole or soufflé dish with a 7 inch diameter. Bake in a pre-heated 350 degree oven for about 40 minutes. Good served with pork tenderloin. (4 servings)