Prawns in Mustard Sauce is a Bengali delicacy made with prawns cooked in a spicy and tangy mustard sauce. The mustard sauce is made from a blend of mustard seeds, green chilies, and spices, which gives the dish a unique and pungent flavor. The prawns are marinated in the mustard sauce and then cooked until they are tender and juicy. This dish is best enjoyed with steamed rice or roti.