Baked Mussels, Potatoes and Zucchini (Tièdda)
This dish gets its name from the vessel in which it's cooked. A tièdda, or tiella or teglia, is a round earthenware baking dish that is deep enough for layering a number of ingredients. The one constant in the dish is potatoes; for best results, use waxy red-skinned potatoes or semi-waxy Yellow Finns but not starchy baking potatoes like Idahos.
At Trattoria Casareccia, a wonderful little home-style restaurant in Lecce, the owner, Concetta Cantoro, makes this tièdda with zucchini and mussels; others might substitute salt cod for the mussels or add a layer of wild mushrooms. The recipe may seem complex, but the mussels, tomato sauce and potatoes can be prepared well ahead of time.