To make the harissa-ish oil, toast your spices in a dry frypan until they are warm and aromatic. Combine all the ingredients in a blender and blitz on high speed until the spices are crushed and well combined. Set aside. This could be done well in advance and kept in the fridge.
Dice your lamb into 2cm pieces and combine with all the ingredients in a bowl. Cover and leave to marinate overnight, or for at least a few hours.
Set up a charcoal grill and get the coals white hot. Thread your lamb pieces onto either metal or bamboo skewers (remember to soak them first if using bamboo), then season with salt. Cook over the fire for 2-3 minutes on each side (you will only flip them once). If your grill is flaring up too much, simply move them for a minute or move the coals around a bit underneath them. Serve immediately with warm flatbreads, some harissa oil, lemon wedges, and a dollop of yoghurt.
