For the sauce:
Heat the ghee or clarified butter in a heavy-bottomed pan. Add the cloves, black cardamom and bay leaf. When they start to crackle, add the onions and cook on a medium heat until they start to turn golden.
Add the turmeric and salt and sauté briskly for a minute, taking care that the dry spice does not start to burn, then add the garlic and stir for a further couple of minutes.
As soon as the fat starts to separate, add the diced lamb and cook until the meat turns slightly brown and starts to get seared on the outside - approx. 4-5 minutes.
Add three quarters of the corn kernels and all the yoghurt and cook on a slow heat for around 30 minutes until the corn is nearly mashed and the sauce starts to become very thick. Add the lamb stock or water.
Bring back to the boil and add the chopped ginger and coriander, then add the remaining corn kernels for texture. Reduce to a medium heat for a further 10 minutes. Check for seasoning and finish with a squeeze of lemon juice.
For the racks of lamb:
Marinate the racks with salt, oil, red chilli powder and ginger and garlic pastes, then leave aside for 20-30 minutes.
To cook the rack, heat a heavy pan with a little bit of oil.
Sear the rack over medium heat for three minutes
Turn it over and cook another three minutes.
Finish in an oven on 175 degrees C for 6-7 minutes and rest the meat for another 3-4 minutes before slicing evenly and placing over the sauce.
Serve with pilau rice.