This originated near the town of Treviso in Veneto, and is more readily available in winter. With long leaves, Treviso radicchio is shaped more like a cos lettuce than the common round radicchio – which is called Chioggia radicchio (after the town where it originated), and can be substituted for Treviso radicchio.
© 2012 Giovanni Pilu and Roberta Muir