Use a firm-fleshed fish, and make sure that it is not ground too fine. Soak the white roll in milk, squeeze it, and shred it. Mix the ground or chopped fish with the roll, one of the eggs, the parsley, pepper and salt.
Make sausage shapes out of the fish mixture, about 6inches long and 1inch thick.
Mix the flour, remaining egg and bread crumbs. Roll the fish sausages in the egg mixture and put them aside.
Heat lard in frying pan; when hot reduce heat to low and very slowly fry the fish sausages, turning them to cook on all sides. Drain them on paper towels. Sprinkle more salt on the sausages if necessary. Serve with mustard sauce.