Radicchio is a bright magenta chicory that looks like a very stylish red cabbage, only with white ribs among its purple leaves, and is smaller and lighter than a head of red cabbage. Radicchio is known for its bitter flavor, which is tempered when cooked. Radicchio is especially high in antioxidants such as flavonoids and phenylic acid. Interestingly, radicchio contains much more antioxidants than other varieties of chicories (such as escarole or curly endive). It also provides vitamins A and C and phosphorus. Choose a heavy head of radicchio with leaves that are spotless, firm and beautiful in their color.