Wash and clean the leeks, chop into thin rings, put in a frying pan with the warmed oil and cook gently. Rinse the dried cod, cut into medium-sized chunks, coat with flour and add to the leeks. Brown the fish on all sides, taking care not to let it stick to the pan. Add the peeled and chopped tomatoes and cook over a low heat for twenty minutes. Sprinkle with chopped parsley and a good pinch of freshly ground black pepper, if liked.
Usually you should not need to add salt to dried cod, but do taste it to check before removing from the heat.
Cod is freshed in the Artic or Antartic and is known either as baccalà or stoccafisso. Baccalà is preserved by salting and has four days to remove the excess salt, while stoccafisso is dried in the open air and has to be soaked for fifteen days then pounded and flaked.