Place the pork rind skin-side down and, using a sharp knife, make lots of light scores in the fat, or ask your butcher to do this for you.
Grind the fennel seeds with 1 tablespoon of sea salt in a pestle and mortar and sprinkle onto the pork, rubbing into the slashes with your fingers.
Using scissors, cut the pork rind into chunks and place on a roasting tray, and place in the oven. As the pork scratchings roast, they’ll release lots of fat – spoon this out every so often and set aside for roasting potatoes.
After 20 minutes, turn down the oven to 160ºC/gas 3 and bake for 35 to 40 minutes, until the scratchings become hard and crispy.
Line a plate with a double layer of kitchen paper, and spoon the scratchings out to drain.