Sweet Potato Pie
["1 uncooked pie shell (bottom crust only)", "2 c. mashed, cooked sweet potatoes", "1/2 c. margarine, softened", "2 egg yolks", "1 1/4 c. packed brown sugar", "1/4 tsp. salt", "1/2 tsp. ginger", "1/2 tsp. cinnamon", "1/2 tsp. nutmeg", "1/2 c. milk", "2 egg whites, beaten stiff with 1/4 c. sugar"]
["Mix", "first", "6 ingredients, starting with sweet potatoes in mixing", "bowl.", "Add\tmilk.", "Fold", "in", "beaten", "sweetened egg whites. Pour", "into", "pie", "shell.", "Bake at 400\u00b0 for 10 minutes. Reduce heat to 350\u00b0 and continue to bake until center is firm, approximately 40\tminutes.", "Nutmeg and sugar may be sprinkled on top of pie before baking, if desired."]
["pie shell", "potatoes", "margarine", "egg yolks", "brown sugar", "salt", "ginger", "cinnamon", "nutmeg", "milk", "egg whites"]