Grind coriander seeds, cumin seeds and red chillies. Heat oil in a pressure cooker. Fry garam masala (whole); add chopped onions and continue frying till golden brown. Add coriander paste. Fry well. Add ginger and garlic. Continue to fry and add mutton pieces. Fry some more and add a teaspoon turmeric, tomatoes, and coconut and khus-khus. Fry for 5 minutes. Add salt and 2 cups of water. Close the lid and cook for 15 minutes. Garnish with coriander leaves and serve.