Heat the oven to 400 degrees.
Peel or scrub your sweet potato.
Using a mandoline slicer set to the thinnest setting, slice your sweet potatoes into very thin slices.
Place the slices in a large bowl. Toss with oil, salt and garlic powder.
Lay sweet potato slices out on 2 baking sheets lined with parchment paper.
Bake the slices for 10 minutes.
Remove the trays from the oven and flip the slices over.
Return to the oven - rotating the trays when you put them back in - and bake for another 10 minutes.
Remove from the oven and sprinkle slices with Parmesan cheese.
Allow to cool to room temperature on the baking sheets before serving.