When people think of grilled vegetables, they don’t often think about grilling a leafy green. But Radicchio has the texture and body needed to stand up to the dry heat of a charcoal or stovetop grill, its pleasing bitterness nicely contrasting with the mild oil used to keep it from sticking and burning. Serves 6 as a side dish. By Terra Brockman, Photos by Cara Cummings