1. Beat egg yolks until light and creamy (two to three minutes).
2. Gradually add four tablespoons sugar. Beat another three minutes. Add potato starch, mixing slowly. Add lemon juice, banana, nuts and wine, mixing another minute.
3. In separate bowl, beat egg whites until frothy. Add four tablespoons sugar and beat until stiff. Gently combine with yolk mixture.
4. Pour into a nine-inch tube pan. Bake at 350 degrees Fahrenheit for one hour.