1. Preheat oven to 250F
2. Combine salt and spices in mixing bowl
3. slice sweet potaoes paper-thin and toss lightly with oil. Toss potaotes with spice mixture until evely coated. Arrange potatoes on wire grates speayed with nonstick vegetable spray or on baking sheets fitted with parchment paper.
4. Bake for 2 hours, then turn off oven and let potatoes dry for 2 more hours or overnight. alternately, dehydrate sweet potato slices in dehydrator according to manufacturers directions.