Preheat the oven to 375 degrees F with the racks positioned in the center. Line 2 sheet pans with parchment paper.

Trim the greens off the beets and wash them with cold water, rubbing off any dirt. Use a mandolin or sharp knife to slice the beets 1/16-inch thick. Wipe off the mandolin or knife between different types of beets.

Place the sliced beets in a bowl or use multiple bowls by color to prevent them from staining each other. Toss the beets with olive oil and kosher salt. Let them sit for 15-20 minutes to allow them to release some moisture.

Arrange the beet slices on the prepared sheet pans in a single layer so they are not overlapping. As you do this, pat off any excess moisture with a towel. (Be careful, the beets will stain the towel.) If all the beets won’t fit on the sheet pans, then bake them in batches.

Bake the beets for 15-18 minutes. Watch them carefully, so they do not brown too much. If you see some chips turning darker faster than others, remove them from the pan and keep baking the other ones until they are done. The chips will continue to crisp up after you take them out of the oven.

Season the chips with black pepper, flaky sea salt and chives before serving.