In a large mixing bowl, combine the dry ingredients. Stir in the oil, lemon juice and lemon rind. In a small bowl, beat the egg yolks with the water and add to the lemon mixture and mix well.

In a clean small bowl, at high speed, beat the egg whites until stiff but not dry. Fold them into the egg yolk-flour mixture. Pour the batter into a 1 1/2 quart casserole or 6 custard cups. Set the dish(es) into a pan containing 1 inch of hot water. Bake in a preheated 350 degree F oven for 40-50 minutes. Serve warm or cold. Serves 6-8.