A very popular Thai soup dish with a combination of healthy and digestive ingredients.
Bring the water to boil over a high heat in a medium-sized saucepan.
Trim off the very end of the lemongrass root and smash with the side of a cleaver or chef’s knife, then cut into 1 inch pieces.
Smash the galangal in a similar fashion and then add the galangal, lemongrass, kaffir lime leaves, fish sauce, tom yum paste and nam prik pao to the water, boiling for 3 minutes.
Add the coconut milk, onion, mushrooms and shelled prawns. Boil for a further 7 minutes until the prawns are pink and cooked through.
Cut the tomato into wedges and add them to the water along with the chillies.
Turn off the heat and squeeze in the lime juice.
Taste to adjust the seasoning, adding fish sauce to taste. Garnish with coriander, spring onion and serve promptly whilst hot.