Soak the wooden skewers in cold water to prevent them burning while you prepare the koftas.
Mix all of the kofta ingredients with your hands in a large bowl until well combined. Shape the koftas onto the skewers.
Barbecue or grill the koftas for 10-12 minutes over a medium heat until browned all over.
While the koftas are cooking make the minted sumac yoghurt by mixing all of the ingredients together in a small bowl. Taste for salt, pepper and sumac.
Serve the koftas with a salad and the yoghurt on the side.