Smash the lemongrass and slice into chunks along with the chillies. Roughly tear the lime leaves and slice the galangal into disks.

Place the lemongrass, lime leaves, galangal and chilli in to the stock and bring to a boil. Simmer on a low heat for 5-10 minutes. Add the evaporated milk and let it come to boil. Tear the mushrooms roughly and add to the soup and cook for 1-2 minutes. Then add the chilli paste or sambal and fish sauce, stir through lastly add the prepared prawns and let them poach in the soup for 1-2 minutes. Make sure the soup isn’t boiling at this point so not to over-cook them.

Turn the heat off and allow to cool for a few minutes before adding the lime juice. This is so that the lime juice doesn’t curdle the evaporated milk. Add the lime juice and stir through. Serve the soup in bowls with fresh coriander and extra lime if necessary.

Note: The herbs are not meant to be eaten, so at this point you can either fish them out, but I like to leave some in there for garnish. Just be sure to tell your guests not to eat them