Wash the beets. Trim off all but about 1 inch of the beet greens (you can save them for later and use them in salads). Leaving on the stem helps keep the beets from “bleeding” out red juice in the oven.
Rub the beets lightly with olive oil. Place the beets in a covered oven proof dish. (You also can wrap each beet individually in aluminum foil and place them on the oven grates).
Roast the beets for 45 minutes to 1 1/2 hours, depending on the size and freshness, until tender when pierced with a fork. Check every 10 minutes until tender; we’ve found medium sized beets take about 1 hour.
Allow them to cool for a few minutes. Then place them under cool water and rub off the skins with your fingers. (It’s a little messy and your fingers will get a little stained, but it’s ok! The beet juice washes off.) Serve immediately, or keep them refrigerated in a sealed container for 3 to 5 days (keep them whole to stay the freshest).