1.Heat oil in a pan on high. Cook lamb in batches for 3 minutes, until browned. Remove from pan.
2.Reduce heat to medium. In same pan, cook onion for 5 minutes, until soft and golden. Add garlic and spices and cook for another 1 minute, until fragrant.
3.Return lamb to pan, reduce heat to low and cook until heated through. Stir in yoghurt. Remove from heat.
4.Place half of rice in a medium flameproof casserole pan and top with half of lamb mixture. Scatter over spinach and season well.
5.Top with remaining rice and lamb. Pour over stock. Cover and simmer on medium heat for 25 minutes, until lamb is tender and rice absorbs stock. Scatter with dropped coriander. Serve with extra yoghurt, if you like.