The tonic bitterness of radicchio is a highly prized quality in the cooking of northeastern Italy. Venetian taste buds thrill to its bracing presence in fish dishes, in risotto, in pasta sauces, somewhat with the readiness with which central and southern Italian palates respond to the excitement of chili pepper in some of the specialties of their regions.
The least bitter of all radicchios, the late-harvest Treviso, can be cooked alone, liberally basted with olive oil and grilled over a slow charcoal fire or baked in the oven. It’s a method that accentuates bitterness and hence it is less suitable to the standard long-leaf Treviso or to the variety best-known abroad, the red cabbage-shaped Chioggia radicchio. But these last are splendid when cooked with mellow-tasting vegetables and become an ideal accompaniment for virtually any meat dish.