Jim'S Favorite Chocolate Pie
["1 pie shell, baked", "1/4 c. flour", "2 eggs, separated", "1 Tbsp. margarine", "cream of tartar", "1/2 c. sugar", "2 Tbsp. cocoa", "2 c. milk", "1 tsp. vanilla"]
["Combine sugar, flour, cocoa, egg yolks, milk, margarine and vanilla.", "Cook in double boiler until thick.", "Pour into pie shell. Top with stiffly beaten egg whites, sweetened to taste.", "Add cream of tartar to thicken.", "Bake at 350\u00b0 until brown."]
["pie shell", "flour", "eggs", "margarine", "cream of tartar", "sugar", "cocoa", "milk", "vanilla"]