1. Preheat oven to 425°.
2. Combine flour and salt in a shallow dish. Combine egg whites and water in a shallow dish, stirring with a whisk. Combine cheese and panko in another shallow dish.
3. Dredge potato wedges in flour mixture. Dip in egg white mixture; dredge in cheese mixture. Divide potato wedges between 2 baking sheets lined with parchment paper. Bake at 425° for 30 minutes or until golden, rotating pans after 20 minutes.