Beet roots can be cooked in a variety of ways (or even eaten raw), but roasting best brings out their natural sweetness.
Preheat oven to 425 degrees. Wrap beets in 2 or 3 packets of foil. Place on a baking sheet; bake until beets are slightly soft to the touch, 45 minutes to 1 hour depending on their size. Cool beets in packets, then rub off skins (use a paring knife for tough spots).