Per Unit. Lemongrass, or citronella, is a herb with a citrus-like flavour. Although lemongrass is central to Asian cuisine, especially Thai, it works well in Western dishes. Also called citronella or sereh, it grows in dense clumps, from which the individual stems are cut. Lemongrass looks a little like fat spring onions with the same swollen base, but the stalk is woodier and composed of tightly packed grey-green leaves. The fragrance and flavour are unique – lemony but sweet – and is quite subtle until the stalk is cut or bashed. You can use lemongrass whole, sliced or pounded to a paste. To use whole, slice off the very bottom of the stalk, peel off any dried-out layers, bash the woody top end with a rolling pin to soften, and help release some of the aromatic oils.