Step 1: Preheat oven to 140°C.

Step 2: Pull rosemary off the stalks and place it in a small bowl. Add extra virgin olive oil, salt, and verjuice to make a slurry.

Step 3: Massage the rosemary slurry mix all over the lamb.

Step 4: Place lamb in a large roasting bag and add any leftover herb mix.

Step 5: Seal the bag, prick once or twice and place in a roasting dish.

Step 6: Slow cook for 4 hours.

Step 7: After this, remove from oven and increase oven temperature to 220°C.

Step 8: Carefully pour pan juices into a jug and put them in the freezer to separate the fat.

Step 9: Remove lamb from oven bag and deglaze with vino cotto or red wine vinegar.

Step 10: Return to the oven and bake for another 15 mins to brown.

Step 11: Remove from oven and allow to rest for a minimum of 30 minutes.

Step 12: Take baking juices from the freezer and remove the fat from the top.

Step 13: Add this to a frying pan. Bring to the boil, then simmer, to reduce down to a rich sauce.

Step 14: Pour this over the roast to enhance the moisture.

Step 15: Carefully pull the meat from the bone with the assistance of a knife if wishing to serve in pieces.

Step 16: Serve with roasted vegetables.