Blend together ¾ c. sugar, ¼ c. cornstarch and ¼ tsp. salt. Slowly stir in 1¼ c. boiling water. Bring mixture to a boil. Reduce heat and boil 1 minute, stirring to keep smooth. Remove from heat. Slowly add ⅓ of hot mixture to 2 slightly beaten egg yolks, then add yolks to hot mixture in pan. Cook over low heat 2 minutes, stirring constantly. Remove from heat. Add ¼ c. lemon juice, 2 tsp. grated lemon peel, 1 tblsp. butter or regular margarine and a dash of salt. Stir until butter is melted and mixture is well blended. Cool.