Lemon Sponge Pie
["1 c. sugar", "3 Tbsp. flour", "1 tsp. grated lemon rind", "2 Tbsp. lemon juice", "1 large egg, separated", "2 Tbsp. butter, melted", "1 c. milk", "pinch of salt", "1 unbaked (9-inch) pie shell"]
["Combine sugar and flour.", "Stir in lemon rind and juice.", "Beat in egg yolk, then melted butter.", "Stir in milk.", "Beat egg white with salt until fairly stiff peaks form, then fold into lemon mixture until no streaks of white show.", "Pour into unbaked pie shell.", "Bake in 350\u00b0 oven 35 to 40 minutes.", "Cool about 15 minutes before cutting."]
["sugar", "flour", "lemon rind", "lemon juice", "egg", "butter", "milk", "salt", "pie shell"]