Wash the sweet potatoes and make sure to scrub the skin (with a vegetable brush).
Then slice the sweet potato lengthwise down the middle. Cut thin slices about ¼ inch (0.5 cm) thick from the middle of the sweet potato. You can keep the skin or discard.
Soak the sweet potato in cold water for about 30 minutes or skip this step and coat the sweet potato with water or oil and cornstarch. Evenly distribute the cornstarch on every slice.
Bake at 220 °C (425°F) for about 20-25 minutes in the oven. Flip the slices halfway.
When your sweet potatoes are done, let cool on a wire rack before adding toppings.