Yummy. Slice sweet potato really thin, with a mandoline or a sharp knife. Toss with a bit of melted butter and/or olive oil. Spread in one layer on a baking sheet. Roast for 15 minutes or so, turning once, until golden and marked with blisters. Remove from oven and toss with sea salt or kosher salt and/or freshly ground black pepper. Enjoy.
You can do the same thing with beets, parsnips, and other root crops.