how to cook beets in oven
1 Cover the baking dish tightly with foil. 2  Roast the beets in the oven for 45 minutes to 2 hours (very large beets may take even longer). 3  Use a pair of tongs to flip the beets every 30 minutes to make sure they roast evenly on all sides. Place a rack in the center of your oven and preheat the oven to 450 degrees F. Line a 9x13 baking dish with foil. 2  As the oven is heating up, prep your beets for roasting. 3  Use kitchen shears to trim leaves and upper stems of the beets, leaving about 2 inches of the stems intact at the top of each beet.