Tom kha: Thai coconut chicken soup with lemongrass and lime
A soup in which nothing is ever boiled hard: coconut cream and stock warmed until the surface trembles, lemongrass and ginger steeped for ten minutes like tea and then lifted out, and at the end chicken, mushrooms and lime juice squeezed in off the heat. Thirty-five minutes, one pot, and a flavour most people associate with restaurants although it is among the simplest things you can cook.
Your own work in that: 25 min.
- Aromatics and chopping 10 min
- Steeping 10 min
- Cooking and seasoning 15 min
Step by step
0 / 6 doneBruise the lemongrass and cut the aromatics
Trim the dry top and the woody base from the lemongrass and flatten the rest with the side of a heavy knife along its whole length, until the stalk splits and smells. Cut into 5 cm pieces. Slice the ginger thinly, crush the garlic with the knife. Cut the chicken into 3 mm slices across the grain, quarter the mushrooms.
Ingredients: 400 ml coconut cream · 400 ml chicken or vegetable stock · 2 pcs lemongrass · 40 g fresh ginger · 400 g chicken breast · 200 g button mushrooms · 2 cloves garlic · 1 tsp sugar · 2 tbsp soy sauce · ½ tsp chilli flakes · ½ tsp salt
TipLemongrass is neither chopped nor eaten — it is as tough as cane. Bruising tears the cells and releases the oils into the broth, and whole pieces are easy to fish out afterwards. Classically galangal is used instead of ginger; ginger is sharper and less resinous, but it is the closest substitute on any shop shelf.
Bruised with a knife, split, in 5 cm lengthsSteep the aromatics in the coconut broth
Combine the coconut cream and stock in a pot, add the lemongrass, ginger and garlic. Heat over low heat until the surface just trembles, but do not let it boil. Take off the heat, cover and leave 10 minutes.
TipCoconut milk is an emulsion of fat in water held together by protein. A hard boil breaks it: the fat surfaces as separate slicks and the soup turns grainy and greasy in the mouth. Kept at a tremble, the emulsion holds throughout the cooking.
The surface trembles, no bubble breaksLift out the aromatics
Fish out the lemongrass, ginger slices and garlic with a slotted spoon and discard them. They have given up most of their aroma, and in a bowl they would be inedible anyway — lemongrass is as tough as cane.
Cook the chicken and mushrooms
Return the pot to low heat. Add the mushrooms and cook 5 minutes, then add the chicken slices and cook another 4–5 minutes, until the meat is white through. Keep the soup at a tremble the whole time.
TipThinly sliced chicken needs four minutes in hot liquid. Cut into cubes and simmered for a quarter of an hour it turns tough and stringy, because above 70 °C the muscle proteins contract and squeeze out their water.
Mushrooms five minutes, chicken fourSeason off the heat
Take the pot off the heat. Add the sugar, soy sauce, salt, chilli flakes and the juice of one lime. Stir, taste, and add juice from the second lime a spoon at a time until the soup is clearly sour, salty and slightly sweet all at once.
Ingredients: 2 pcs limes · ½ bunch fresh coriander · 150 g jasmine rice
TipLime juice always goes in at the end and off the heat. Boiled, it loses its fresh citrus aroma and leaves only sourness, and acid in the hot soup can split the coconut milk as well. The coriander also goes in only at the end.
Off the heat: lime, sugar, sauce, chilliServe
Ladle into bowls, scatter with coriander and a pinch of chilli, and set a lime wedge on the rim. Serve on its own or with a bowl of jasmine rice alongside. Keeps 2 days in the fridge; reheat very gently and never let it boil.
Coriander, chilli, lime on the rim
Before you start
With prawns instead of chicken
300 g prawns added for the last 3 minutes, once the mushrooms are tender. Cooked longer they turn rubbery; they are done when they curl into a C.
Vegetarian
Vegetable stock, 300 g button and oyster mushrooms instead of chicken, soy sauce in place of fish sauce and cubed tofu at the end. Here the flavour comes from the lemongrass and lime, not the meat.
When there is no lemongrass
A wide strip of zest from one lime plus an extra centimetre of ginger, steeped the same way. Not the same thing, but closer than a soup with no citrus backbone at all.
