1. Grind the onion and tomato coarsely.
2. Heat oil in a pressure pan/cooker and add ginger garlic paste.
3. Add the ground tomato and onion.
4. Let it fry for a while, add salt and let it soften.
5. Add the mutton chops toss and fry for 2-3 minutes.
6. Add chilli and coriander powder.
7. Add 2 cups hot water.
8. Close and pressure cook for 15 mins till the mutton cooks.
9. Let cool and open; let it boil till the gravy thickens.
10. Add chat masala and garam masala cook till the gravy reduces to a thicker consistency till almost dry.
11. Sprinkle chat masala and coriander leaves before serving.
12. Your chatpata mutton chops is ready.

Tip: Use cooking soda to make mutton cooking easier to some extent either while pressure cooking or after pressure cooking.