Wash and cut the mutton into small size pieces. Keep it on a colander for it to drain completely.
Heat oil in a pressure cooker, add onion julienne, slit green chilies and saute well.
When the onions start browning, add the Mutton Masala and cook till the masala is cooked well.
Next add the drained mutton pieces and mix everything well.
Bring to boil, you will find the mutton leaving a lot of water, it should almost evaporate.
After about 10 mins or so, add coriander powder, red chilli powder, salt, turmeric and mix well.
Add 1 -2 cups of water and cover with lid. Pressure cook till done.