Preheat the oven to 400 degrees. Cut the greens off the beets, leaving about ½ inch of the stems still attached. Save the greens for another time. Wash the beets well and place them in a roasting pan or pie plate with a thin layer of water on the bottom. Cover tightly with foil. Roast about 50 minutes (or longer for larger beets). When the beets are done, carefully remove the foil. Allow them to cool, and then peel them by slipping off the skins with your fingers. Cut them into ½-inch wedges. You can also slice some thinly into rounds and cut some into wedges.Lower the oven to 350°. In a pie plate or baking sheet, toast the hazelnuts until the skins blister, about 15 minutes. Transfer the nuts to a clean kitchen towel and let cool, then rub to remove the skins. If you don’t mind hazelnut skins, you don’t need to remove them. Coarsely chop the nuts.When ready to plate the salad, pull burrata apart with your hands and mound it down the middle of a platter.Arrange the beets alongside the burrata, sprinkle with hazelnuts, sliced mint, salt and pepper, and drizzle with olive oil and balsamic.