Pat'S Chocolate Pie
["4 Tbsp. cocoa", "1 1/2 c. sugar", "6 Tbsp. flour (all-purpose)", "4 eggs, separated", "2 c. milk", "1 Tbsp. butter", "1 Tbsp. vanilla", "1 (9-inch) pie shell", "1/2 c. sugar", "1/4 tsp. cream of tartar"]
["Combine cocoa, sugar and flour in medium saucepan.", "Set aside. Beat yolks.", "Gradually stir yolks and milk into mix. Add butter. Cook over medium heat until thick.", "Stir constantly. Remove and add vanilla.", "Put into shell.", "Beat egg whites.", "Wait 6 minutes. Bake at 400\u00b0 until light brown."]
["cocoa", "sugar", "flour", "eggs", "milk", "butter", "vanilla", "pie shell", "sugar", "cream of tartar"]