In a pressure cooker, melt about half the amount of ghee, add the ginger garlic paste and turmeric powder.
Saute and then add the mutton pieces with salt. Cook in the ghee for few minutes and then add water.
Pressure cook the mutton for 3-4 whistles. Strain the mutton pieces and keep aside. Do not throw away the broth.
Now dry roast all the masalas mentioned under the "Chettinad masala", along with chillies and then grind into smooth paste with little water.
Heat a heavy bottomed kadhai with the remaining amount of ghee, then add the curry leaves followed by the remaining ginger garlic paste.
Stir it for few minutes and then add the roasted masala paste. Stir for few minutes and then add the curd, salt and lemon juice while continuously stirring it.
Once the masala is cooked, it would leave oil on the sides, add the mutton broth into it and bring upto boil.
Then add the pressure cooked mutton and stir it. The gravy consistency depends on personal preference, you can either keep enough gravy or dry it up. Serve with hot rice.