Preheat oven to 170C/340F and line two baking trays and set aside. (SEE NOTE 2)
Using a mandoline, (on the thinnest setting), slice your potatoes to produce uniform, thin rounds around 1.5-2mm thick.
(Optional - SEE NOTE 3) Soak your potatoes in a bowl of water for 30min - 1 hour.
Ensure your rounds are dry by placing them on a clean dish towel and patting them dry.
Add a single layer of sweet potato rounds to the baking tray, being careful not to overlap.
Brush, (or spray), both sides of each round with oil.
Bake for approx 20mins, turning the potatoes halfway through the cook time. (SEE NOTE 4)
Remove from oven and allow the chips to sit in the baking tray for a further 5 mins. This helps to crisp them up. If you have any soft chips after this, return to the oven for another couple minutes.