Preheat the oven to 160ºC/325ºF/Gas3. 

Place the Pork in an ovenproof roasting tin and rub salt all over the skin, add the water to the bottom of the pan and roast for 2½ hours.

Lift the Pork from the pan and add the potatoes, place the pork back on top of the potatoes and roast for another hour, remove from the pan and cover loosely with foil leaving to rest for 10 minutes before serving.

Serve with glazed baby leeks and apple sauce.