Heat oil in the pressure cooker. Saute the onions till it becomes lightly brown.
Meanwhile, grind the green chillies, ginger paste, garlic paste, coriander powder and fennel seed with a little water till it becomes like a paste.
Once the onions are browned, add the paste, chilli powder and turmeric powder and saute till the raw smell goes.
Add the tomato and saute for a couple of minutes.
Now add the washed mutton and salt, combine well till the masala gets coated.
Close the lid of the pressure cooker and cook for a couple of whistles.
Lower the flame and leave for 5 minutes. Now switch off the flame and leave for the pressure to go by itself.
Open the lid, switch on the flame and put on simmer. Add the garam masala, sugar and coriander leaves and give it one last mix. Serve with chappathi or rice!
Notes
The curry will just have the mutton stock in it. If you want it more thicker, just keep on simmer till all the stock is dried.