Radicchio and Lobster Salad

There is something irresistible about the radicchio and endive families, especially when paired with lobster. My favorites are the three from Treviso (excluding the fourth, the rounded one with compact leaves called Chioggia, which one sees most often)—the incredibly beautiful lettuce-shaped one that is creamy light green with purple shot through it (Castelfranco), the slightly blanched one with small leaves called Treviso tardivo, and the full Belgian endive-shaped one with big long