Macha Jhal is a traditional Bengali dish made with Hilsa fish and a flavorful mustard paste. The fish is marinated in a mixture of mustard paste, turmeric, and salt, and then cooked in a spicy mustard gravy. The dish has a rich and tangy flavor, with the mustard paste adding a unique kick to the fish. It is usually served with steamed rice and is a popular choice during festive occasions in Bengal.