Kosha mangsho is a traditional Bengali dish made with tender mutton cooked in a rich and spicy gravy. The dish is known for its deep, dark color and intense flavors. The mutton is marinated with yogurt, spices, and mustard oil, then slow-cooked with onions, ginger, garlic, and a blend of aromatic spices. The slow cooking process allows the flavors to develop and the meat to become tender. Kosha mangsho is typically served with steamed rice or Indian breads like roti or paratha.