Thailand has two really famous soups: tom yam (or tom yum) and tom kha gai (or tom kha kai). Both are complex and delicious, filled with exotic aromas and flavours. Such is the genius of Thai cuisine that although the two soups contain many of the same ingredients, their characters are completely distinct: tom yam takes on a fiery heat and slight sourness from the addition of tamarind chili sauce (nam prik phao), while tom kha gai is silky smooth because of the inclusion of sweet and mellow coconut milk. I love them both, but this one is my favourite. The recipe above is pretty good, but not mine is a little different (and more authentic in both ingredients and method.
A note on the name: tom means boil or boiled in Thai, kha is galangal or galanga, and gai or kai is chicken, so this is something like "boiled galangal chicken"; elsewhere on e2 this soup has been referred to as galanga curry. More usually on menus in Thai restaurants it's something like coconut chicken soup. Yam, by the way, means mix, so tom yam is "boiled mixed", hardly a good translation of what is more generally referred to as spicy sour soup.
What you'll need
- 5 cups (1.2 litres) chicken stock (or lemongrass broth, or water if you must)
- 3 or 4 stalks of lemongrass, tough outer layers removed, cut into 2 inch sections and whacked once or twice smartly with a chef's knife or pestle to release the aromatic oils
- 6 or 8 lime leaves, torn into 2 or 3 pieces
- a chunk of galangal, unpeeled, sliced into 7 or 8 pieces the size of a large coin
- 3 or 4 roots, with perhaps half an inch of stem attached, from sprigs of coriander (cilantro), well washed; reserve the leaves for garnish
- 2 tblsp (30 ml) fish sauce (nam pla), or 2 tblsp (30 ml) Golden Mountain Sauce or 2 tsp (10 ml) salt for vegetarians
- 1 can (14 oz/400 ml) coconut milk
- 1 boneless chicken breast, cut into bite-sized chunks
- 1/2 lb (225 gr) oyster mushrooms, pulled into thin strips, or button mushrooms, sliced
- 1 tsp (5 ml) palm sugar or brown sugar
- 3 or more hot Thai chilis
- 2 scallions, chopped, for garnish
What to do
Note: We all know that homemade stock will give the best results, but in this soup, plain water will do in a pinch. That's because of the aromatics - lemongrass, galangal, lime leaves, coriander roots - which impart amazing aroma and flavour. Note that they are not meant to be eaten; Thai people know this, and so just push these sticks and leaves to the side when they encounter them in their soup. If it bothers you to have inedible chunks in your soup, put them in a cloth bag or piece of cheesecloth so they won't be floating about in the finished product.
On to the soup. Bring the stock to a boil in a heavy-bottomed pot and add the aromatics, free or bound in a bag. Then turn the heat down and simmer (don't boil), uncovered, for 10 minutes or so to bring out their flavour. Things should start to smell good.
Add the fish sauce and coconut milk and increase the heat slightly, but don't let it boil or the coconut milk will curdle. That's the only tricky thing about this recipe.
Add the chicken and cook for about 5 minutes, till the flesh is mostly cooked, then add the mushrooms and cook till they soften, perhaps 3 or 4 minutes.
Now the soup is almost ready. Stir in the lime juice and sugar. Whack the chilis once or twice with a chef's knife or pestle to release their oils, and plunge them into the soup. I recommend leaving them in for up to 1 minute and then removing them; it will only take one eaten by mistake to convince you that this removal is a good idea. These babies are hot. Also, if you've put your aromatics in a bag, remove them too.
Garnish the soup with chopped coriander and scallion and eat.
In Thailand this soup is served in a large doughnut-shaped pot with a flame burning underneath; the intent is to keep the soup warm as you proceed through your meal. Nice touch, but who has such a thing here? I serve the soup in a large bowl, and give each diner a small bowl and one of those flat-bottomed Chinese soup spoons and ladle a little out for each person, explaining about the twigs and leaves you're not supposed to eat.
As with most Thai dishes, this soup is not a separate course, but one of the many dishes that grace the dinner table, to be eaten with jasmine rice and whatever other wonderful dishes strike your fancy, such as a stir fry or two or a curry. I personally wouldn't serve this with a curry that contains coconut milk - too much of a good thing - but any other Thai dish will help round out this soup and make an amazing meal that will wow yourself and your guests.