Aunt Irene'S Chocolate Pie
["3 egg yolks", "1 2/3 c milk", "5 Tbsp cocoa", "2 Tbsp cornstarch", "1 1/4 c sugar", "1 tsp vanilla", "1 tsp butter", "1 baked pie shell (9 inches)", "Meringue recipe below*"]
["Beat egg yolks and part of the milk in a saucepan. Then add sugar mixed with cocoa and cornstarch. Stir the mixture very well. Add remaining milk, vanilla and butter and mix well. Cook until thickened. Pour chocolate mixture into a baked pie shell. Cover with meringue if desired."]
["egg yolks", "milk", "cocoa", "cornstarch", "sugar", "vanilla", "butter", "shell", "Meringue recipe below"]