Mix sugar and flour, add melted butter, lemon juice, grated rind and salt. Add beaten egg yolks and milk. Add stiffly beaten egg whites.
Pour into unbaked pie crust and put into preheated over at 400 for 10 minutes. Reduce heat to 300 and bake until firm and nicely browned. Cooking times vary depending on using regular crusts or deep dish, the top of the pie will look like a cake crust.