Sweet Potato Custard
["3 c. sweet potatoes, cooked and mashed", "1/2 stick butter", "1 egg", "1 c. sugar", "1 (9-inch) unbaked pie shell"]
["Mix all ingredients (except pie shell) and put in unbaked pie shell.", "Bake in a 350\u00b0 oven for about 25 minutes."]
["sweet potatoes", "butter", "egg", "sugar", "shell"]