You want to start by cleaning the prawns. Remove the head and the shells and set them aside. Using a toothpick remove the view that runs through the body. You can ask your fisher monger to clean it for you but also ask for the heads and shells.

Heat a tablespoon of oil in your wok and fry the shrimp heads after you season them with a bit of salt.

Cook them for 3-4 minutes of a medium-high heat till their colour changes and some fond develops on the pan. Then deglaze the pan with the water and stir well to get any of that fond off the bottom. Cover and cook for 10-15 minutes on a low heat.

After the stock has simmered remove the heads and the shells with a slotted spoon. Then add in the lemongrass, galangal, kaffir lime leaves and half the chillies. Make sure you bruise the lemongrass with a rolling pin, slice the galangal into rounds, tear the kaffir lime leaves and chop the chillies.

Cover and cook for 10 minutes on a low heat till everything is infused. Then add in the chilli paste, fish sauce, cream and mushrooms and cook for a further 5 minutes.

Finally add in the prawns which will cook in 2 minutes. Add in the coriander as they cook. Then turn off the stove and finish with the lime juice. Taste everything once for season and add salt if required.

Serve!