Salt cod with prunes

All over the Catholic countries of Europe, fish is eaten on Christmas Eve, a day of pasting and abstinence, and in the land-locked areas this is most often salt cod. I have eaten this dish many times at Valvona and Crolla; it is Philip Contini’s (mine host) favourite dish and Mary has given me the recipe. The prunes should be plump and stoned; if dried, soak in advance.