A main ingredient in Thai and South-east Asian cuisines, lemongrass is a pale green stalk that can be used fresh, dried or powdered to impart its lemon flavour to sweet or savoury dishes. Fresh stalks are sold in many supermarkets now.
If used whole, the lemongrass pieces are always removed from the dish before serving, but some recipes use it finely chopped or pounded into a paste.
It keeps in the fridge for about a week. If you can't buy lemongrass then substitute lemon zest.