Adapted from a recipe in "Plenty", by Yotam Ottolenghi. Will serve two as a vegetarian main course salad, or four as a side salad. A sprinkle of crumbled feta or similar cheese on top is also delicious.
Cover beets with cold water in a pot, bring to boil, cook 1 to 2 hours, depending upon size, until they are easily pierced by a knife or metal skewer. Let beets cool in the water, then drain them and peel them. Cut each beet into wedges about 1 inch wide and place them in a mixing bowl.
Cut the oranges into supremes by cutting off the tops and bases, then cutting down the sides, following the natural curve, to remove the peel and pith. I find a boning knife works best for this. Over a small bowl, remove the segments by slicing between the membranes. Add the segments and any captured juice to the bowl of beet wedges.
Coarsely chop the radicchio into one-inch pieces and add to the bowl of beets. Add remaining ingredients and toss. Taste, adjust seasoning, serve.