Mix together ginger, garlic, fresh coriander, olive oil, lemon zest, juice and harissa paste in a bowl. Add all the dried spice ingredients and mix well.
Score the leg of lamb with a sharp knife, making cuts around 2 cm deep. Rub the marinade over the lamb using your hands, working into the cuts
Leave to marinade for at least 3 hours or in a fridge overnight.
Place the lamb and marinade into the Crock-Pot bowl. Cover and cook the lamb on Low for 8-9 hours or High for 7-8 hours
Once cooked, baste the lamb with the liquid and leave to rest before slicing.
(For crispy skin, transfer to a pre-heated oven at 200C for 20 minutes before resting.)
Serve with a tomato salad and flatbreads