3 egg yolks
1 c. sugar
2 tbsp. cornstarch
1/3 tsp. salt
2 c. boiling water
4 tbsp. vinegar

Beat egg yolks in double boiler until light and lemon colored. Sift together cornstarch, sugar and salt. Stir into beaten egg yolks. Add boiling water gradually. Add vinegar. Cook until mixture thickens. Pour into baked pie shell. If you wish, top with meringue.