Combine egg whites, cream of tartar, and salt in a mixing bowl.
Beat until soft peaks form.
Add flavoring of your choice.
Beat to stiff peaks.
Spread over bottom and sides of 8 or 9 in. (20 or 23 cm) pie pan.
Bake at 275°F (135°C) for an hour or until lightly browned and crisp.
Cool before filling.