Pat dry the lamb with paper towel and place it on a baking tray.

Remove the flesh from the skin of the preserved lemon. Rinse the skin and discard the flesh. Roughly chop the preserved lemon skin and place in a food processor with the sea salt, ½ of the bunch of oregano and garlic cloves. Blitz to form a paste. . Rub this mixture into the lamb, massaging well. Place the lamb in the fridge (not covered) overnight.

Take the lamb out of the fridge at least 1 hour before you start cooking so that it is as close to room temperature as possible.

Use a baking dish that will fit the lamb, and that has a lid. Place the sliced onions and the remaining half bunch of oregano on the base of this large roasting dish.

Preheat oven to 110°C.

Place a large frying pan (large enough to hold the lamb shoulder) on medium-high heat. Brown the meat on all sides; it will take about 10 minutes to get a good colour all over. Transfer the lamb to the baking dish & place it on top of the onions and oregano.

Place the frying pan back on the heat and select medium heat. Pour in the wine and let it bubble, and reduce for 2 minutes. Pour the warm wine over the lamb.

Pour the vinegar around the lamb and add the lemons. Sprinkle with freshly cracked black pepper and cover with a lid and bake on the middle shelf for 12 hours. Check every so often to ensure the onions are not burning, and baste the lamb.

When it is ready, the meat will be incredibly tender and falling off the bone.

Gently shred the meat into large pieces and use the roasting juices to moisten the meat.