Koi Mach, also known as Climbing Perch, is a popular Bengali fish dish. The fish is marinated in a flavorful mixture of spices and then fried to perfection. The dish is known for its crispy texture and delicious taste. It is often served as a main course with steamed rice and a side of mustard sauce. Koi Mach is a must-try for seafood lovers looking to explore the rich flavors of Bengali cuisine.