Step 1: Prepare the Marinade

Blend chopped onions, garlic, yogurt, salt, garam masala, and turmeric until smooth.

Step 2: Marinate the Mutton

Pour the prepared marinade over the bone-in mutton pieces. Mix well to ensure all pieces are coated. Marinate in the refrigerator for 1-8 hours or preferably overnight.

Step 3: Prepare the Spice Mix

In a small bowl, combine cumin powder, coriander powder, and Kashmiri red chili powder. Add about 1/4 cup of water and mix well to form a paste.

Step 4: Sauté Whole Spices

Heat 1/2 cup of mustard oil in a large kadhai (wok) over medium heat. Add dried Kashmiri red chilies, bay leaves, black cardamom, cinnamon stick, cloves, and green cardamoms. Sauté for about 30 seconds until fragrant.

Step 5: Brown the Onions

Add the sliced onions to the kadhai. Cook on medium heat for about 8-10 minutes, stirring frequently, until they turn nice and brown. If some onions brown faster, add a splash of water and stir to ensure even browning. Repeat as needed until all onions are evenly browned.

Step 6: Add Ginger Garlic Paste and Green Chili

Once onions are browned, add 2 tablespoons of ginger garlic paste and 1 de-seeded and chopped green chili. Sauté for 1-2 minutes until the raw smell disappears.

Step 7: Add Spice Mix

Pour the prepared spice mix into the kadhai. Cook for a couple of minutes, stirring continuously, until the spices are well incorporated and fragrant.

Step 8: Cook the Mutton (First Phase)

Add the marinated mutton to the kadhai. Turn the heat to high and sauté the mutton for about 5 minutes, stirring constantly, until it starts to brown and caramelize.

Step 9: Add Yogurt and Sugar

Reduce the heat to medium. Add 1/4 cup of yogurt and 1 teaspoon of sugar to the mutton. Mix well until combined.

Step 10: Slow Cook the Mutton (Kosha Style)

Add 1/2 cup of water to the kadhai. Cover and cook for 10 minutes at a time. After each 10-minute interval, open the lid, stir the mixture, and scrape any browned bits from the bottom of the pan. Continue this process for 1-2 hours, or until the mutton is tender, the liquid has significantly reduced, and the gravy has turned a thick, dark brown color. This is the "kosha" technique, intensifying the flavor.

Step 11: Adjust Gravy Consistency

Once the mutton is tender and the gravy is thick, you can add a small amount of water (approx 1/4 cup) if you prefer a thinner gravy. Stir well.

Step 12: Final Touches

Finish the dish by adding 2 sliced de-seeded green chilies and a generous dollop (1 tablespoon) of ghee. Stir gently.

Step 13: Serve

Serve the hot Kosha Mangsho with jeera rice or sweetish pulao.

• Marinate mutton overnight for best results.

• Constantly stir onions and mutton during the slow-cooking process to prevent sticking and build flavor.

• Add small amounts of water during onion browning to ensure even caramelization.

• Adjust water at the end for desired gravy consistency.

• Adjust green chilies and Kashmiri red chili powder for desired spice level.

• Serve with sweetish pulao or jeera rice.