Pour water in a cooking pot and bring to a boil.
Put-in galangal, lime leaves, lemon grass, tamarind paste, and fish sauce. Stir well and simmer for 5 minutes.
Add the shrimps and simmer for 3 to 4 minutes.
Put-in the onion, straw mushrooms, and chili paste then simmer for another 5 minutes.
Add chili and tomato then simmer for one minute.
Put-in the lime juice and cilantro then turn off the heat.
Transfer to a serving bowl.
Serve hot. Share and enjoy!