Preheat oven to 400.
Wash beets well. Either wrap in foil OR brush with olive oil and place in baking dish.
Place wrapped beets or baking dish in preheated oven and roast 1 - 1 1/2 hoyrs, depending on size. test for doneness by poking with a skewer or fork, if easily pierce, ther're done.
Allow to cool slightly, peel and use as desired.