This purple lettuce-like vegetable is grown in Veneto, and is a specialty of nearby Treviso. There are various different kinds, and it has a bitter taste. You can eat it raw or cooked in pasta or as a side dish. The best season for radicchio is winter. Varieties include Treviso and Chioggia, and there is even a light pink one grown on Vignole island (sold at the Lido food market on Tuesdays and Fridays).