You will need:
- 1 C coconut milk
- 1 1/2 water (or chicken stock)
- 1 stalk of lemongrass, cut into 2" pieces and crushed with clever
- 6-8 thin slices of Galanga, crushed (preferably fresh, otherwise frozen)
- 1 C bite-size pieces of chicken
- 1 C mushroom, thinly sliced
- 3-4 fresh (or frozen) Kaffir lime leaves, TORN in half
- 3-4 fresh chili peppers, crushed
- 2 Tbsp fish sauce
- 1/2 tsp salt
- 3 Tbsp lime juice
- 1 tsp sugar
- 1 green onion, chopped
- 1/4 C chopped cilantro
Galanga (also known as Galangal. Laos Root, and Thai or Siamese Ginger) - or "Kha" in Thai - is the main herb flavor that gives this rich and aromatic soup its fame. If fresh galanga is not available, frozen galanga will work great for this dish. I've seen many recipes suggest using ginger as a substitute. Believe me, it's completely different soup you would make there! Ginger doesn't have distinct peppery and lemony flavors galanga has. ... So, for me -- if there is no galanga, there is no Tom Kha Gai soup. Anyway, if you find galanga root at Oriental market, it can be stored in freezer really well; just slice into pieces and put then in zip-lock bag. Same thing can be done with lemongrass as well; just cut into 2" pieces before freezing them. In the meantime, dried galanga might be found easier, but I don't recommend using it as it doesn't give as good flavor as fresh or frozen ones.
- In a sauce pan, combine coconut milk, water, galanga, and lemongrass, then bring to a boil.
- Add chicken, fish sauce, salt, and sugar. Reduce heat to medium-high.
- Once chicken is cooked, about 2-3 minutes, stir in mushroom, chili peppers, and kaffir lime leaves.
- About another 2-3 minutes until mushroom is cooked and the flavors are all married, then turn off the heat. Stir in lime juice, green onion, and cilantro. Serve immediately.
- Some recipes call for adding "Nam Prik Pao" (or Thai Roasted Chili Paste) to the soup. It is optional. The chili paste adds some color and spices up the dish.
- For a vegetarian version, medium or firm tofu is a good substitute for chicken.
- Remember, you can always adjust the flavor to your preference. Fish sauce and lime juice are the main seasonings you can add more or reduce.
- Just like most Thai dishes, this soup is not a separate course, but one of the many dishes that are on the dinner table, to be eaten with jasmine rice.