2 medium beets, scrubbed and tops removed
l sweet potato, scrubbed
l T. extra-virgin olive oil
l tsp. flaky sea salt

Preheat the oven to 250°F. Line two large baking sheets with parchment paper. Slice the vegetables about Vs inch thick. Use a mandoline, if you have one, to create even pieces. Place the beet slices in one bowl and the sweet potatoes in another. Divide the olive oil and salt between the bowls and toss the slices to coat. Place on the prepared baking sheets without letting the slices touch. Place the baking sheets in the oven. Rotate the pans after 1 hour and continue to bake until crisp, a total of 1 hour 50 minutes to 2 hours for the beets and 1 hour 40 minutes for the sweet potatoes. Transfer the chips to a large bowl and serve immediately. Best right away, but leftovers will keep for up to 3 days in an airtight container.