Galangal, lemongrass, kaffir lime leaves, coriander root, chilli, lime juice… In this famous soup Thai flagship ingredients’s flavours are perfectly recognisable, one by one, creating a recurrent mixture of sour, salty and hot flavours, embellished with a typical sharp aroma. This dish perfectly illustrates the elegance and sophistication of Thai cuisine one might not necessarily see throughout years of eating sloppily prepared curries, served in so many restaurants in Europe (and maybe elsewhere too).
“Tom kha gai” means roughly a dish with galangal (tom kha) and chicken (gai) and this soup does contain a particularly high dose of galangal root, which slightly dominates it. I have followed here the recipe from David Thompson’s Thai Food (a most extraordinary cookery book I recommend to every Thai food lover) and as the author suggested, apart from the chicken, I added also some delicate-tasting mushrooms (oyster mushrooms proved perfect). (In the meantime I made a test with cultivated button mushrooms (aka “cremini”, when they are brown) and their taste was too strong).
I tried to make this dish as close to the original as possible, but I won’t pretend it is (mainly due to what I did with coconut milk and cream). I have cut down the coconut milk amounts and skipped the coconut cream, replacing both liquids with more chicken stock. The original version was just too fatty and rich for me. (In fact I do this very often in Thaï dishes, just like I cut down on cream and fat in Western cuisine). I have also added more chicken meat and more mushrooms in order to make it a very filling one-course meal, easily served with rice or bread; not to mention the amounts adapted to a dish for two. I encourage you to check the extraordinary David Thompson’s Thai Food for the original recipe.
TIPS: This dish is a good way to test if you are able to cook certain genuine Thai dishes… because its ingredients appear in almost every curry (and I assume curries are what most Thai food lovers try to make at home first). In short, if you can find fresh (or at worst frozen) lemongrass, kafir lime leaves, galangal root and coriander roots, then you are almost ready to buy David Thompson’s book without being utterly frustrated (there are some other products, such as fresh peppercorns, Thai basil, holy basil, grachai, kaffir lime zest… but these aren’t used as often as former ingredients). From my experience, the smallest damage through freezing is done to kaffir lime leaves and coriander roots. Lemongrass and galangal become mushy and the galangal’s taste changes, but it’s still better than using dried versions.
Coriander roots are particularly difficult to get for some people, but I have recently read on a forum a fantastic trick: buying a potted plant in a gardening shop! Of course, if you are able to grow your own herbs on a balcony, windowsill or in a garden, finding roots should no longer be a problem. You can also ask a farmers’ market vendor to bring you next time coriander with roots or only roots (I’m sure many would happily give them for free).
If you use frozen kaffir lime leaves (I can find them here only frozen), double the amount because they are less aromatic (in general, if using frozen vegetables in Thai dishes, I increase their amounts).
Preparation: about 30 minutes
Ingredients (serves two):
400 ml chicken stock
250 ml coconut milk
1 big chicken breast (skinned)
250 g oyster mushrooms, tough stalks removed (or other delicately flavoured mushrooms)
7 thin slices of fresh galangal
pinch of salt
1/2 flat teaspoon palm sugar
1 big thick stalk lemongrass or two thin stalks (whole, only the tough end trimmed)
2 small Asian red shallots (I have used 1 medium European shallot)
1 big coriander root
2 red bird’s-eye-chillies + 2-3 more for the final serving stage
2 kaffir lime leaves (if you have frozen lime leaves, see the TIPS)
2 tablespoons fish sauce (or more)
1 tablespoon lime juice (or more)
Pour the stock and the coconut cream into a pan.
Bring to the boil.
In the meantime wash the mushrooms and tear them into bite-sized pieces.
Slice very finely the chicken breast and sprinkle with salt (do not add too much salt).
Place the shallots, the lemongrass stalk, the coriander root and the bird’s-eye-chillies in a mortar and bruise them with a pestle. You can also do it, placing them on a cutting board and using an ice “pestle” for cocktails (this is what I did) or any other heavy object.
Put aside 2-3 chillies for the final serving stage.
Place the remaining bruised vegetables into the boiling stock, adding salt, palm sugar, galangal and lime leaves.
Let it simmer for about ten minutes.
Add the mushrooms and after 5 minutes, the finely sliced chicken breast.
Continue simmering until the mushrooms and the chicken are done.
Mix the lime juice, the fish sauce, the additional bird’s-eye-chillies and the coriander leaves in an empty serving bowl. Pour the soup over it, stir well, adjust the taste – the author says it should taste rich, salty, sour and hot, though if you have “thinned” the stock, as I did it won’t taste very rich – and serve.
I prefer dividing the sauce, the juice, etc. into individual bowls and then putting the fish sauce and a piece of lime on the table, so that I can still adjust the taste.