Mustard oil

Mustard oil is the pungent, deep-golden fat pressed from the seeds of brown or Indian mustard (Brassica juncea), and it is the defining cooking oil of Bengal, Bangladesh, Odisha, Assam and much of North India. Sharp, hot and sinus-clearing when raw, it is traditionally heated to smoking before cooking — a step that tames its bite and unlocks its characteristic aroma. Its assertive, almost horseradish-like pungency is so central to the cuisines built on it that no other oil substitutes for it in flavour. It is sold as kachi ghani (cold-pressed) sarson ka tel and, confusingly, also as a fragrance oil where food use is restricted.