Kosha Mangsho is an iconic Bengali mutton curry celebrated for its deep, robust flavors and rich, dark-brown gravy. Prepared using a traditional slow-cooking method, tender pieces of mutton are carefully seared and then braised with caramelized onions, yogurt, and a fragrant blend of aromatic spices until the meat becomes irresistibly succulent. The word kosha refers to the slow sautéing and reduction process that concentrates the flavors, creating a thick, intensely flavorful gravy. A beloved centerpiece of Bengali festive meals and family gatherings, this hearty delicacy typically serves four and requires about two hours of preparation and slow cooking to achieve its signature melt-in-the-mouth texture and depth of flavor.
Kosha Mangsho is an iconic Bengali mutton curry celebrated for its deep, robust flavors and rich, dark-brown gravy. Prepared using a traditional slow-cooking method, tender pieces of mutton are carefully seared and then braised with caramelized onions, yogurt, and a fragrant blend of aromatic spices until the meat becomes irresistibly succulent. The word kosha refers to the slow sautéing and reduction process that concentrates the flavors, creating a thick, intensely flavorful gravy. A beloved centerpiece of Bengali festive meals and family gatherings, this hearty delicacy typically serves four and requires about two hours of preparation and slow cooking to achieve its signature melt-in-the-mouth texture and depth of flavor.
Combine mutton with all the marination ingredients in a bowl. Mix well to coat the meat thoroughly, cover, and refrigerate for at least 3 to 4 hours (overnight is best).
Heat mustard oil in a heavy-bottomed pan or pressure cooker until smoking, then slightly lower the heat. Add bay leaves, dried red chilies, cardamom, cloves, and cinnamon.
Add the sugar and sliced onions to the tempered oil. Fry on medium-low heat until the onions turn a deep, rich golden brown.
Add chopped tomatoes along with cumin powder, coriander powder, and any remaining chili/turmeric. Cook for 5 minutes until the oil starts to separate from the spice paste.
Add the marinated mutton to the pot. Sear and fry the meat on medium-high flame for 15 to 20 minutes. This slow-frying process is the secret to the dish—stir continuously until the meat releases its juices and darkens in color.
Add 2 cups of hot water, stir, and close the pressure cooker lid. Cook on medium-low flame for 7 to 8 whistles (or until mutton is tender).
Let the pressure release naturally. Open the lid, simmer for a few minutes if the gravy needs thickening, and stir in the Bengali garam masala and ghee.