Preheat air fryer to 350°. In a large bowl, combine mashed potatoes, cheeses, shallot, rosemary, sage, salt and pepper; stir in turkey. Mix lightly but thoroughly. Shape into twelve 1-in.-thick patties., In a shallow bowl, whisk egg and water. Place bread crumbs in another shallow bowl. Dip croquettes in egg mixture, then in bread crumbs, patting to help coating adhere., Working in batches, place croquettes in a single layer on greased tray in air-fryer basket; spritz with cooking spray. Cook until golden brown, 4-5 minutes. Turn; spritz with cooking spray. Cook until golden brown; 4-5 minutes. If desired, serve with sour cream.