Cut the skin from a piece of belly pork or a joint of loin of pork. It can be from any piece of the pig. Leave a layer of fat under the skin about 2 cm(¾ in) thick.

Use a very sharp knife to cut the pork skin into 6 cm(2½ in) squares. Make a few gashes across the fat side to help the fat melt more quickly.

Take a cast-iron casserole or pan and, when quite hot, add the pork skin, fat side down; shake the pan now and again to ensure that the pork has not stuck to the base.

Transfer the pan to a slow oven (Mark 2, 150°C, 300°F) for 3–4 hours. Or cook on the hob, set at low to medium, over a heat-spreading mat, for 2–3 hours or until the grattons are golden and crisp, like the best crackling, and the fat has totally melted.

Pour off the liquid fat and reserve for cooking potatoes; lift out the grattons, sprinkle with salt and serve. In country districts they are served with a plate of pureed potatoes.