Pat the leg of lamb dry using a paper towel. Then place on a chopping board bottom-side up. Slice along the bone to create a cavity for the spices and to reduce the cooking time. A forequarter leg of lamb can be completely butterflied, while a hind-quarter would be more difficult to butterfly.

Liberally apply salt to the bottom and top of the lamb roast. A smaller leg of lamb can get away with 2 teaspoon of salt, but crank it up to 4 if you have a large 2kg leg of lamb.

Combine the olive oil, lemon juice and herbs, and massage into the leg of lamb. Place on a roasting rack or place the lamb on slice onions and garlic within a roasting dish. Allow the lamb to rest anywhere from 30 minutes to 1 hour. If you are resting the lamb for longer than an hour - you can leave it in the fridge.

Before you roast your leg of lamb, allow it to come to room temperature for approximately one hour.

Preheat the oven to 200°C (fan-forced). Roast the lamb for 20 minutes, then turn down the oven to 180°C and cook for a further 40 minutes, or until the internal temperature is 60 - 62° C for medium-well lamb.

BUT - if you have completely butterflied the leg of lamb, you will reduce the cooking time by half. In that case - roast for 20 minutes at 200°C for 20 minutes, and turn down the oven to 180°C and cook for a further 20 to 30 minutes.

Place the roast leg of lamb on a plate, cover with foil and allow to rest for 20 to 30 minutes before carving and serving.