Place all of the Crust ingredients into a blender and blend until they form a paste.
Slash the lamb on both sides and spread the crust ingredient mix over the lamb shoulder (leave to marinade overnight if you can).
Prepare the BBQ for indirect cooking and place the lamb above a pan.
Cook either low and slow 225F (for approx 6 hours) or hot and fast 350F (for approx 4 hours) until the lamb is soft and almost falling off the bone. During the final hour of the cook, place the lamb in a pan and cover with foil.
During the last half hour of the cook, smoke the Beetroot (I tend to use fresh cooked beetroot and just smoke to add flavour).