This intensely fragrant herb is used to impart a lemony flavour to many dishes and can also be used as a skewer for satays. Cut off the roots and use only the tender bottom portion (16-20 cm / 6-8 in ). Discard the hard outer leaves. If a whole stem is added to a gravy during cooking, it should be bruised a couple of times with the edge of a cleaver or pestle to release the fragrance, then tied in a knot to hold it together.