Clean ginger, garlic and green chillis properly and make a smooth paste.
Chop onion and keep aside
Clean mutton properly and drain it. In a big mixing bowl add cleaned mutton, chopped onion, ginger garlic paste, salt (1tsp), zeera powder 1tsp, dhania powder 1tsp, vinegar, haldi powder 1tsp and mustard oil. Mix properly and marinate it and keep aside.
In a pressure cooker heat mustard oil, add sugar and let it caramelize. Add vay leavesto that, now add ginger, garlic and green chilli paste. Saute ( bhuno) it up to the paste started to stick to the spatula. Then add chopped onion and saute up to all the spice come together.
At this time add chopped tomatoes to this and also add all the dry spices except garam masala. Saute up to oil separates from the masala. Then add marinated muttom. Fry up to all the water evaporates from the meat.
In the mean time cut all the potatoes into halves. Heat ghee in a pan and add the potatoes, salt and haldi. And fry the potatoes up to golden brown.
When water evaporates from the meat add the potatoes to the meat. Fry it properly. Add water upto the meat level and cover the cooker. Cook up to the two whistles ( 1 in high and 1 in low). Let it allow to cool down.
When the pressure cooker realise the pressure add garam masala , chopped coriander leaves and salt if needed.
Serve hot with rice