Cut off the beet greens. Scrub the beets under cold, running water until clean. Blot dry with paper towels.
Use a sharp knife to cut off both ends of the beets. Cut them in half if large or quarter them if very large. Place beet chunks on a large sheet of heavy duty foil. Drizzle with olive oil. Enclose the beets in the foil, sealing tightly. Place foil packet on a rimmed baking sheet and transfer baking sheet to the oven.
Roast for 45 to 55 minutes, or until fork tender. Remove from oven and allow to cool. When beets are cool enough to handle, use a paper towel to easily remove peels.
Store beets in an airtight container in the refrigerator for up to a week.
Be sure to roast different colored beets in separate foil packets.