Put the stock and tom yum paste in a pan and add the lemongrass and ginger. Bring slowly to the boil then simmer for 5 minutes. Add the chilli, fish sauce and prawns and cook for 2 minutes.
Remove from the heat and ladle into bowls, scatter over the herbs and serve with some lime wedges, if you like.
Tip Stir in coconut milk to give a thicker, richer tom yum soup
See more Thai recipes
This recipe is perfect for making in large batches and freezing to use at a later date.
In order to enjoy optimum flavour and quality, frozen items are best used within 3 months of their freezing date.
Always defrost and heat thoroughly before eating. Never re-freeze food that has already been frozen; this includes raw and cooked ingredients such as meat, fish and poultry.