Marination: Clean, wash and drain the mutton/beef.
In a small bowl, whisk together yogurt, ginger paste, garlic paste, oil and salt. Add this to the mutton and mix well. Marinate for 2-3 hours in the refrigerator.
Spice mix: Coarsely grind the green cardamoms, black cardamoms, cloves and cinnamon sticks.
In a pressure cooker, add oil, coarsely ground spice mix and bay leaves. Sauté for a minute and add sliced onions.
Once the onions are soft, add ginger and garlic paste and sauté until fragrant.
Add marinated mutton and sauté on high until the mutton changes color (5-10 minutes).
Add chopped tomatoes and cook on high until the water released from the mutton and tomatoes is evaporated and the oil has been separated from the gravy. This would take around 15-20 more minutes and the raw smell of the meat would also be gone by the end of this process.
Now add potatoes, salt, red chili, turmeric, coriander powder, cumin powder and give a few stirs. Add water to cover the curry.
Pressure cook for 3 whistles (12-15 minutes) or until the mutton and potatoes are done.
Lastly, sprinkle garam masala, add green chilies and garnish with freshly chopped coriander.