1 kilogram salmon carcass (head, bones, tail)
8 cups water
1 large galangal
4 stalks of lemongrass mashed lightly
2 coriander roots with skin scraped off
10 small shallots
10 kaffir lime or bergamot leaves
3 prik chee fah deseeded (These are bigger but less spicy than bird’s eye chili. You can substitute with bird’s eye chilies but will need to adjust the quantity.)
1 cup coconut milk
240 gram fresh salmon cut into 1 cm cubes (40 grams per person)
3-4 tablespoons lime juice
Coriander and kaffir lime leaves and fried dried chilis (for sprinkling on top of the salmon)
This is my take on Tom Kha Gai or Chicken Galangal Soup. It was actually based on my craving for bouillabaisse. I chose salmon because even if it's overused in Thai cuisine, not many places do it right. It always come over cooked.
I also wanted a soup that is thick but not heavy. So I added mashed salmon meat. The hot soup is then poured over fresh salmon to cook it just right.
I omitted mushrooms in this recipe simply because I don't like mushrooms in galangal soup. You can add them if you want.
Wait for the above to come to a boil again before adding the salmon carcass. And do not stir until the water comes to a boil again.
I don’t know the scientific explanation behind it, but this is a common Thai tip for cooking fish. You only add or stir when the water is boiling hot. Doing this will ensure that the soup won’t smell fishy in a bad way.
2. When the water is boiling again, turn down the heat to low. Let simmer for an hour or until there are about 2 cups of stock left.
3. Strain the soup and throw away the galangal, shallots, coriander roots and lemongrass. Set aside. Pick out the salmon meat from the carcass. You should get about 3/4 cup. Mash finely, pick out any stray bones and add back to stock. This will give you a flavorful and thick soup without being heavy. At this point, you can also freeze the stock for later use.
4. Just before serving, put the salmon cubes into individual bowls. Top with fried chilies and coriander leaves. Set aside.
5. Bring the stock to a boil. Add the coconut milk and chilies. And if you want mushrooms in the galangal soup, this is the time to add them. Crush the lime leaves with your hands to release the aromatic oil and tear them into tiny pieces. Add into soup. When it comes to a boil again, season with fish sauce and palm sugar. Use the palm sugar sparingly. It’s just to round off the taste not make the soup sweet.
Bring it off the heat. Add the lime juice. Give it a quick stir. Taste again. The soup should be a harmonious blend of sour, salty, and spicy. If not, add more of the seasoning as needed.
Pour the hot soup over the fresh salmon cubes, and serve.
There you have it. Thick salmon galangal soup with salmon that is cooked just right.