Seared Radicchio with Raisins and Shaved Parmigiano

This warm salad is made with a naturally sweet, high-quality balsamic vinegar to balance the bitterness of the leaves. If top-shelf balsamic vinegar di Modena is unavailable or out of your price range, cooking the grocery store version down by about one-third of its volume over a medium-low flame—and further sweetening it to taste with a drizzle of honey as needed—helps produce a similar level of sweetness.