Heat oil in a pressure cooker and add finely sliced onions. Saute till it becomes golden brown colour. Add ginger & garlic paste & crushed small onion & curry leaves. Fry for a few minutes. Mix the masala powders with a little oil or water and add to the curry. When the raw smell of masala is gone & oil starts appearing, add cleaned mutton pieces and salt. Mix well & saute for 5 minutes. Add water & cover and cook till the mutton is done.
If there is excess water, let it evaporate completely. Transfer the curry to a non stick pan and cook on low flame till it is roasted well. (If your pressure cooker is non stick, you can do this process in the cooker itself.)