Wash and pat dry lamb chops. Tie yogurt in a muslin cloth and hang it for half an hour to drain out the whey. This should preferably be hung in the refrigerator.
Transfer the hung yogurt into a bowl and add raw papaya and salt. Marinate the lamb chops in this mixture for about two hours, preferably in the refrigerator.
Dry roast coriander seeds, cumin seeds, cloves, black cardamoms, mace, black peppercorns and dry red chillies. Cool and powder. Heat oil in a pan, add onions and sauté for three to four minutes or until light golden brown. Add ginger paste and garlic paste and stir-fry briefly.
Add prepared spice powder, Kashmiri chilli powder and cook on medium heat for two minutes.
Add the marinated lamb chops along with the marinade, one cup of water and bring to a boil. Reduce heat, cover and cook for fifteen to twenty minutes or until the mutton chops are completely cooked.
Add tomatoes and cook on high heat for four to five minutes, stirring frequently. Ensure that the gravy is quite thick. Garnish with coriander leaves and serve hot