Mom'S Chocolate Pie
["3 Tbsp. cocoa (heaping)", "3 Tbsp. flour", "1 1/2 c. sugar", "3 egg yolks (save whites)", "1 1/2 c. milk", "1/4 tsp. cream of tartar", "1 deep-dish shell or 2 shallow shells"]
["Bake shell according to instructions provided. Mix all dry ingredients together in saucepan. Add rest of ingredients and cook over low heat until thick. Pour in baked pie shell."]
["cocoa", "flour", "sugar", "egg yolks", "milk", "cream of tartar", "shell"]