Lemon Meringue Pie
["1 (9-inch) baked pie shell", "1 c. sugar", "1/4 c. flour", "3 Tbsp. cornstarch", "1/4 tsp. salt", "2 c. water", "3 egg yolks, beaten", "1 Tbsp. margarine", "1 tsp. grated lemon peel", "1/4 c. lemon juice", "3 egg whites", "6 Tbsp. sugar", "1/2 tsp. cream of tartar"]
["Mix all ingredients together and cook over medium heat until thickened.", "Stir constantly.", "Remove from heat and pour mixture into baked pie shell.", "Beat egg whites and sugar, adding cream of tartar until stiff.", "Spread on pie and bake until brown."]
["shell", "sugar", "flour", "cornstarch", "salt", "water", "egg yolks", "margarine", "lemon juice", "egg whites", "sugar", "cream of tartar"]