Preheat oven to 450°. Scrub and trim ends off small beets; if you can get both red and gold, so much the better. Slice 1/8" thick and toss with olive oil, kosher salt, and thyme. Place on parchment-lined baking sheet(s) in single layer. Roast for 20–25 minutes, until beets are soft and shrunken, slightly glistening on top, and dark around the edges. (The thinnest slices will be crisp and almost burned around the edges.) Yum, yum.