Eel and Onion Casserole

Comacchio is the centre of the eel-fishing industry, and here is one of the most traditional and simple recipes for cooking this surprisingly delicious fish. The local method for removing the scales from the fish is to rub the whole length of it with handfuls of wood ash, placed on sheets of robust paper. You can substitute dogfish, buss or rock salmon for the eel. Whatever type of fish you are using, you could ask your fishmonger to prepare it for you and cut it into 2 inch (5 cm) pieces.