For the lamb koftas, mix the lamb mince, onion, chilli powder, cayenne pepper and flour together in a bowl.
Remove the leaves from the rosemary stalks, leaving some leaves at the tip. Using wet hands, shape the lamb mixture around the three rosemary stalks. Rub the oil onto the outside of the koftas.
Heat a griddle pan over a high heat and cook the koftas, turning frequently, for 4-5 minutes, or until the koftas are golden-brown and cooked through.
For the yoghurt dip, mix all the ingredients together in a bowl and season, to taste, with salt and freshly ground black pepper.
To serve, place the lamb koftas onto a serving plate with the yoghurt dip.