Pour the water into a pot, add the lemon grass, galanga, goat pepper and kaffir-lime leaves and heat it.
2. Add the shrimps when the water is boiling and cover the pot.
3. Wait for 3 minutes before adding the mushrooms, tomato and salt.
4. Leave it to simmer for a few minutes. Add evaporated milk and chili paste. Then remove from the heat.
5. Season with fish sauce and lime juice.
6. Put the chopped coriander leaves in the pot before serving.