Mom'S Chocolate Pie Filling
["7 Tbsp. cocoa", "2 Tbsp. butter", "2/3 c. flour", "2 c. sugar", "1/2 tsp. salt", "5 c. milk", "8 eggs, separated", "1 1/2 tsp. vanilla", "2 baked pie shells"]
["Mix cocoa, butter, flour, sugar, salt and egg yolks in heavy saucepan (save egg whites for meringue).", "Add milk a little at a time.", "Stir constantly over medium-high heat until thickened. Remove from heat and add vanilla.", "Pour into two baked pie shells."]
["cocoa", "butter", "flour", "sugar", "salt", "milk", "eggs", "vanilla"]