Method

Make the rosemary oil first by adding the oil into a blender, the picked sprigs of rosemary (remove the hard stalks) and the salt and pepper to taste and blitzing to a paste

Rub the rosemary oil onto the leg of lamb, cover in cling film and pop into the fridge overnight.

You can make the baste the night before by crushing up the garlic and placing into a small sauce pan with the oil, lemon juice and zest, anchovies as well as the butter and quickly bringing up the heat so the butter is melted and the sugar has dissolved. Take off the heat and pop this into the fridge once cooled.

You’ll want to take the lamb out of the fridge a few hours before the BBQ so that it comes back towards room temperature and ensures a far more even cook

When the BBQ is fired up and ready, move most of the coals to one side so that the lamb will sit in an area of medium yet constant heat.

Place the lamb on the prepared spot in the bbq and close the lid. Cook for about an hour and try not to lift the lid too often as you want to keep the heat in

After an hour, you can start to baste the meat so place the saucepan of paste on the BBQ to warm up and melt and baste every 5 minutes for another 30 minutes.

When done, take off the BBQ carefully, cover in tin foil to rest for about 20 minutes and then serve