Preheat the oven to 220C/425F/Gas 7.
Mix all dry ingredients together and toast in a dry pan. Crush in a pestle and mortar or blend in a spice grinder to powder. Mix the lamb, the lime zest and juice and all the toasted ingredients together. Form on to wooden skewers and put aside to rest.
For the yoghurt sauce, miix the yoghurt ingredients togetherin a bowl and set aside.
Heat an ovenproof griddle pan until smoking and add the koftas. Griddle on all sides to achieve brown char marks, then transfer to the oven to cook for ten minutes, or until completely cooked through.
Serve on a plate with chopped coriander sprinkled over the top and some of the yoghurt mixture.
