Radicchio (Cichorium intybus) is an Italian leaf chicory grown for its striking wine-red leaves veined in white, packed into a head that is round and cabbage-like in the Chioggia type or long and tapering in Treviso. Eaten raw it is crisp and assertively bitter, a clean astringent bite that wakes up a salad; cooked, that bitterness mellows and turns nutty and faintly sweet, which is why it is as often grilled, roasted, braised or stirred through risotto as it is shredded into leaves. A cornerstone of the cooking of the Veneto in north-east Italy, it pairs naturally with fat, sweetness and acid — olive oil, balsamic, aged cheese, toasted nuts and orange — that round off its edge. It is a chicory, a bitter relative of endive and escarole, not a red lettuce.