In a 1- 1/2 quart saucepan or the top of a double boiler, beat eggs well. Combine the sugar and potato starch and gradually whisk them into the beaten eggs. Stir in lemon juice and water. Then over low heat or over simmering water in the bottom of the double boiler, cook pudding mixture slowly, stirring constantly until the mixture is thickened and bubbles begin to appear. Remove from heat.
Pour or spoon into individual dessert cups or dishes and set aside to cool slightly before serving. Or refrigerate until ready to serve.