Preheat the oven to 300°F. Prepare a baking sheet by fitting it with a large cooling rack.
Using a sharp knife, cut the sweet potatoes into thin, even slices, no more than ⅛-inch thick. Transfer the sweet potato slices to a large bowl and toss with the oil and salt. Arrange in a single layer on the cooling rack (some slight overlap is ok).
Bake for 30-40 minutes, flipping every ten minutes, or until curling and browning around the edges. Let cool completely on the cooling rack, then store in an airtight container.
Notes
Tip: Use a mandolin for even, thin slices. This ensures that each and every chip is the same thickness, so you don't end up with a few crispy chips and a handful of soggy ones.