Cook cushaw until done and rub through sieve. Cream a good sized lump of butter with 1 1/2 cups sugar, yellow of 4 eggs and 2 1/2 tablespoons flour. Then add cushaw and 1 1/2 cups of sweet milk. Season with ginger and cinnamon. Cook mixture in double boiler until thick.

Bet egg whites, sweeten and stir into the mixture. Bake in tart shells and top with whipped cream just before serving.