If you're cooking your own beets, do that in advance. Preheat the oven to 425°F and line a baking sheet with parchment paper. Remove the tops and the roots of the beets and peel each one with a vegetable peeler. Cut the beets in 1 ½ inch chunks, then toss the beets in a bit of olive oil. Roast in the oven until the beets are tender, 30-35 minutes. Let them cool to room temperature.