I’ve made tom kha gai many times before we took a cooking class in Chiang Mai. But there’s nothing like learning from a Thai chef. That was when I realized that there’s a huge difference between good and great Thai chicken coconut soup.
What exactly did I learn in Chiang Mai about cooking tom kha gai? Two things, mainly. The first is using the correct herbs and spices. The second is choosing coconut cream over coconut milk.
Correct herbs and spices
The correct herbs and spices, the seasonings to make a good balance of flavors and the patience to create a good spice base make up the backbone of great tom kha gai. And when we talk about “correct herbs and spices”, we must understand the nature of each ingredient to know which can withstand substitutions and which you simply have to use or not cook the dish at all.
Let’s start with galangal. It looks a bit like ginger but the flavor is simply not the same. I used to think it was okay to use ginger if I couldn’t find galangal. Fresh galangal is not widely available in the Philippines, I used to make do with crushed galangal in jars and when even the latter was inaccessible, I simply substituted ginger.
Huge mistake especially when cooking Thai dishes like tom kha gai. After all, the name of the dishtranslatesto chicken (gai) cooked (tom) with galangal (kha). Without galangal, the dish would be tom gai, not tom kha gai.
In the collage above, the dried galangal is on the top left. The other herbs and spices that you simply cannot ditch or insist on finding substitutes for are lemongrass, kaffir lime leaves, chili and cilantro. I wouldn’t even recommend substituting a portion of a large onion for the shallots because large onions are simply too bland.
Coconut cream, not milk
- If using freshly grated coconut (should be mature, of course), squeeze the coconut without adding water to get pure coconut cream.
- If using canned coconut cream, chill unopened in the fridge for a few hours. Open the can and scoop out the thick cream that floats on top. Use that and discard the liquid underneath.
- If using powdered, dissolve in the least amount of water to make coconut cream.
Tom kha gai
For the spice base
- 4 slices galangal - (rehydrated if using dried)
- ¼ cup sliced lemongrass - (lower portion of the stalk only)
- 2 pairs kaffir lime leaves - ribs removed
- 2 shallots - peeled and roughly chopped
- 1 bird's eye chili - (use more for more heat)
- 2 tablespoons coriander roots and stems
- 2 slices ginger
- 1 teaspoon fish sauce
- 1 tablespoon coconut sugar - dissolved in a teaspoon of water to make a paste
To make the soup
- 4 cups chicken bone broth
- 6 chicken thigh fillets - cut into thin slices
- 2 eryngii (King oyster) mushrooms - cut into thin slices
- 1 plump tomatoes - diced
- 8 stalks scallions - cut into two-inch lengths
- 1 whole stalk lemongrass - tied into a knot
- fish sauce
- 2 cups coconut cream
To finish the dish
- ¼ cup lime juice
Make the spice base
- Grind all the solid ingredients in the spice base list. Pour in the fish sauce and diluted coconut sugar slowly to make grinding easier. You don't need to make a paste. You just want to pound everything to small pieces.
Cook the soup
- Pour the chicken bone broth into a pot and add the spice base. Bring to the boil.
- Stir in the chicken, mushrooms, tomato, lemongrass, scallions and a tablespoon of fish sauce.
- When the broth starts to boil, lower the heat, cover the pan and simmer for about 10 minutes.
- Pour in the coconut cream.
- Over medium heat and with the pot uncovered, continue cooking the soup over a gentle boil until the chicken and mushrooms are cooked through.
- Taste the soup. Add more fish sauce if too bland.
- Off the heat, stir in the lime juice.
- Taste and adjust the amount of fish sauce and lime juice, if needed.
Serve your tom kha gai
- Ladle the soup into bowls. Sprinkle with torn cilantro and serve.