Put the ghee in a large, sturdy casserole over a medium heat.
When hot, add the whole spices and fry for 1 minute.
Add the onion and fry for 10 minutes until softened and golden.
Stir in the garlic and ginger, fry for 1 minute.
Add the ground spices (reserving the extra garam masala and ground fennel) and fry for 30 seconds.
Stir in the tomato puree, then add the lamb and salt and stir to make sure the lamb is well coated in the other ingredients.
Pour in the water, bring to a simmer, then cover the pan, reduce the heat to low and simmer gently for 1 hour or until the lamb is tender.
Stir in the yoghurt and cream, then season with the extra garam masala and ground fennel.
Scatter with the fresh coriander and serve.
