Step 1

Combine harissa, oil, garlic and coriander in a bowl. Place lamb, skin-side down, on a board. Rub lamb all over with spice mix. Place in a large glass or ceramic dish. Cover. Refrigerate for at least 2 hours, to allow flavours to develop (see note).

Step 2

Preheat a barbecue plate or grill (with hood) on high heat. Remove lamb from dish. Reduce heat to medium-high. Barbecue lamb, skin-side down, for 10 minutes. Turn and cook for 5 minutes. Reduce heat to medium-low. Cover lamb with barbecue hood. Cook for a further 15 to 20 minutes for medium or until lamb is cooked to your liking. Remove from heat. Cover loosely with foil. Set aside to rest for 10 minutes.

Step 3

Slice lamb. Season with salt and pepper. Serve sprinkled with extra coriander.