Heat the ghee in a heavy-bottomed pot. Add the onions and cook slowly until golden brown. Remove and set aside to cool.
In the same pot, add the lamb. You shouldn’t need extra oil as the fat will render out. Fry until browned all over.
Add the korma masala and mix well so the lamb is fully coated.
Pour in 500 ml of water and bring to a gentle simmer. Slowly stir in the yoghurt, then add the green chillies.
Cover with a lid and cook on low heat for 1.5–2 hours, until the lamb is soft and tender. Remove the lid and continue simmering until the sauce thickens.
Blitz the fried onions with a splash of water to form a smooth paste. Stir this into the curry once the sauce has reduced.
Finish with fresh coriander and serve hot with naan or rice.
Notes
Cook's Tips:Packet masalas are perfect for consistent flavour, but feel free to make your own spice mix when you have the patience. To save time, use a pressure cooker. A 15-minute pressure cook will take this from a 2-hour recipe to roughly 45 minutes from start to finish. Lamb shoulder gives the softest texture, but lamb leg works if you prefer something leaner.