Heat ghee in a pressure cooker (or any thick bottom pan) and fry the mutton pieces for 2 minutes till the juices are sealed and meat has changed color slightly.
Now add onion, tomato, salt, chili powder, ginger and garlic paste.
Mix well and cook on high heat for 1 minute. Place the lid on and cook till mutton is almost cooked.
Once the mutton is cooked, add coriander powder, garam masala powder, black pepper, and lemon juice. Stir well and cook for 5 minutes on low flame without placing the lid. You need to reduce all the extra moisture in the gravy.
Finally add yogurt, coriander leaves, and green chilies and cook for another 5 minutes. Check the seasoning*and adjust accordingly. If you want the dish to be spicier, add more green chilies.
Garnish with more green chilies and fresh coriander leaves and serve hot.