Lock the lid and pressure cook until it reaches high pressure. After the first whistle, cook on medium heat for 40 to 45 minutes (note 5). Turn off the flame and allow the pressure to release naturally.
Meanwhile, heat a teaspoon of oil in a pan. Roast a handful of curry leaves until they turn aromatic and crisp. Remove from the pan and keep aside.
Heat the remaining oil in the same pan. Add a bay leaf and transfer the contents from the pressure cooker to the pan.
1½ teaspoon pepper, ½ teaspoon garam masala
Stir intermittently for about 15 to 20 minutes until the gravy thickens and browns.
By now the pieces of meat will be so soft that the bones will almost fall apart. Transfer mutton masala to a serving bowl and garnish with chopped coriander leaves and roasted curry leaves.
Serve with steaming hot rice, dosa or roti.
If you're using bone-in mutton, get it chopped into bite-sized pieces from your butcher, cutting through the bones of the mutton can be quite a struggle.
When you are cleaning the mutton, wash a couple of times with plain water, and for the last rinse, add 1/2 teaspoon of turmeric to the water to disinfect and remove the raw smell from the meat.
Ensure that the meat is at room temperature when you start cooking.
I did not add water to the pressure cooker since the moisture in the rinsed mutton is enough to cook the gravy. (Mutton also leaves a lot of moisture while cooking.) If your mutton pieces are absolutely dry, feel free to add ¼ cup of water.
The cooking time highly depends on the quality of the meat and size of the mutton pieces. The meat of a younger goat cooks faster- you can make out from the color of the meat, it has more of a pinkish tint.
Test the mutton for doneness: After pressure-cooking, the mutton should be soft and give in if you apply slight pressure. If you find the mutton is tough, pressure cook again, allowing 10 minutes after the first whistle. (Remember to add a little hot water, say ¼ cup if the gravy has dried up.) Let the pressure release naturally.
Cooking mutton masala in an instant pot: Follow the same cooking instructions, using "normal" mode on the "meat" setting (that is 35 minutes at high pressure). Allow the pressure to release naturally. You can remove the cooked mutton, rinse and use the pot on "saute" mode for the rest of the cooking.
Serving suggestions: Best served with plain boiled rice, flavored rice or naan/roti.
Make-ahead option: Since this goat masala has no dairy or coconut cream, it keeps well in the refrigerator for 4 days (or more) and 2 months in the freezer. Ensure that you store in an airtight container.