Wash sweet potatoes and slice thinly with a mandoline slicer or sharp knife. No need to peel the potatoes.
Place potato slices in a bowl with oil and sea salt. Start with 1/2 Tablespoon of oil and add more if needed. You want the sweet potato slices lightly coated. Toss to combine until all slices are lightly coated with oil.
Set slices in a single layer on a baking sheet and bake for 40-50 minutes, flipping the chips every 15 minutes and watching them carefully as some might start to brown faster than others.
Chips are done when they're golden in color and crisp.
These chips are best eaten right away, but they can be stored in an airtight container for 1-2 days. If they get soft, you can pop them back in the oven to crisp up again before serving.
Notes
You can also use a dehydrator to make sweet potato chips. Lay chips on dehydrator sheets and dehydrate at 125°F for 12-20 hours or until crisp.