Step #2 Trim any excess fat off the outside of the lamb & then cut into 5cm chunks.
Step #3 place this in a non metallic bowl with the oil, garlic, spices, lemon juice, harissa & some seasoning & mix well.
Step #4 Cover up & leave to marinate at about room temp for 2 hrs.
Step #5 Peel the onion, leaving the root end intact, & then cut into 8 wedges so that the slices of onion stay together at the root of each wedge.
Step #6 Cut the lemon into 8 wedges.
Step #7 Thread the lamb chunks & lemon & onion wedges alternately onto four 30cm flat metal skewers, & place over medium hot barbecue, for 10 - 15 mins.
Step #8 Turn every now & then, until the lamb is nicely browned on the outside, but still pink in the centre.
Step #9 Serve with fresh coriander & roasted pumpkin wedges, if liked.