In a grinder jar, finely blend onion, green chillies, garlic cloves, ginger, black peppercorns, and coriander seeds into a smooth paste. Strain the blended mixture through a sieve to eliminate any coarse particles.

Marinate the mutton pieces in a mixing bowl with the ground paste, degi mirch powder and salt. Cover the bowl with a cling film or a plate and refrigerate for at least 2 hours.

In a pan, heat oil over high heat. Add the sliced onions and fry until they achieve a golden brown hue. Take them out of the pan, coarsely grind in a blender, and set aside for later use.

Heat ghee in a large pot over medium-high heat.

Add the dry spices- cinnamon stick, green cardamoms, cloves, black peppercorns, bay leaves, and star anise into the oil. Stir them briefly for a few seconds.

Next, add the curd and continue stirring consistently for 3-4 minutes until the curd starts to curdle.

Add nutmeg powder and mace powder and stir to mix.

Combine the marinated mutton with the spices in the pot, and sear the mutton on high heat for about 8-10 minutes, allowing the flavours to meld.

Mix in the ground onion paste and cook for 4-5 minutes, stirring occasionally.

Add water to the pot and mix. Bring to a boil, cover with a lid and cook on low heat until the mutton is tender. (approx 1.25 hours). Stir occasionally.

Check the seasoning and adjust to taste.

Add Kewra essence and cashew paste and mix well. Adjust the consistency of the gravy by adding water if needed.

Garnish with fried onions (barista) and serve hot with roti or naan.