This grilled radicchio salad is a tasty way to cook up your greens. Radicchio is an Italian lettuce that has a bitter flavor. It ranges in color from dark purple to light green. The heat transforms this lettuce completely and the flavor becomes mild and smoky. This dish is delicious served with a few shavings of Pecorino cheese or tossed with some orzo pasta. If radicchio is unavailable in your area, this same technique can be used with Romaine lettuce.