Peel the sweet potatoes and slice them thinly.
Soak the sliced sweet potatoes in water for 10 minutes.
Pour an appropriate amount of cooking oil into a bowl and add a pinch of salt.
Add the drained sweet potatoes to the bowl and mix well to coat them evenly with oil.
Spread the sweet potato slices on a baking tray (or air fryer tray) in a single layer so they do not overlap.
Bake in the oven (or air fryer) at 210°C (410°F) for 10 minutes, then flip and bake for an additional 5 minutes. (Adjust temperature and time to your preference.)