Mildred'S Chocolate Pie
["1 c. milk", "3 eggs", "2 Tbsp. cocoa", "1 c. sugar", "1 Tbsp. flour", "1 Tbsp. butter", "1 tsp. vanilla"]
["Cook the first six ingredients until thick; add vanilla. Reserve whites for meringue."]
["milk", "eggs", "cocoa", "sugar", "flour", "butter", "vanilla"]