Dry roast the whole spices in a heavy bottomed pan or a cast iron skillet over a low heat, until they release their essential oils. Grind them using a coffee grinder. Marinate the mutton pieces with the ground spice mix overnight or for around 4-6 hours in a refrigerator covered with a lid.
Put the ghee in a heavy bottomed pan, and heat it on medium to high until it starts to smoke.
Reduce the heat and add the cinnamon and black and green cardamoms followed by the cloves and peppercorns. Sauté them in the ghee, making sure they don’t burn.
Add the fennel seeds followed by the marinated meat and turn the meat so it is coated evenly with the oil.
Cook until the meat slowly changes colour, becoming a light brown.
Add the asafoetida at this point followed by the ground ginger, covering the meat, and cook for another minute.
Next, add the red Kashmiri chilis followed by the rattan jot root and water.
Mix well, coating the meat thoroughly. Finally, fold in the yoghurt till it coats the meat. Add salt to taste.
Cover the pan and cook on a low flame for about one and a half hours or until the meat is cooked and the rogan (red oil) comes to the surface, rendering the finished curry with a glossy red look.
Add a little hot water occasionally and cook until the meat is done.
Serve sprinkled with coriander leaves, naan, and rice.