Thai Chicken Soup with Sweet Potato and Lemongrass Recipe
An aromatic, mildly spicy soup with chicken, sweet potato and lemongrass is a homemade version of Thai street food that in Thailand is eaten at any time of day. It’s as warming as Polish chicken broth in winter, but scented with lime, ginger and coconut. Perfect when you’re craving something exotic yet still simple to make in one pot.
This recipe is loosely inspired by tom kha gai – the classic Thai coconut soup – where traditional galangal and kaffir lime leaves are replaced here with easier‑to‑find ginger, sweet potato and lime.
Instead of curry pastes this soup uses fresh aromatics – lemongrass, ginger, chili and lime – so it’s easy to make with ingredients from a larger supermarket. The flavours are bold but familiar, which makes it a good “gateway” into Thai cooking for people who love classic chicken broth.
Why this version works
- Sweet potatoes stand in for harder‑to‑find Asian vegetables and naturally thicken the soup.
- The lemongrass is simmered in whole pieces and removed, so you get the aroma without any fibrous texture.
- Adding the coconut milk at the end protects it from curdling and keeps the texture smooth.
- Seasoning with lime juice right at the end lets you balance the sourness perfectly to your own taste.
Chef's tips
If you’re using stock made from a cube, reduce the amount of fish sauce and add it gradually, tasting after each addition so you don’t oversalt the soup. The ideal moment to stop cooking is when the soup is silky and creamy with a gentle sheen on the surface, but without distinct oily droplets. When reheating the next day, finish with fresh coriander and a squeeze of lime, because citrus aromas fade quickly.
How to serve
Serve it on its own as a hearty soup, or with jasmine rice in a separate bowl so you can drop spoonfuls into the soup like dumplings. It works well as a main course on a chilly evening or as a warming packed lunch in a thermos, with extra lime wedges and chili on the side.
Watch out for
- Do not let the coconut milk come to a rolling boil, as it can split.
- Don’t cut the sweet potato into pieces that are too large – the outside will fall apart before the centre softens.
Substitutions
- You can replace the chicken with firm tofu cut into cubes; add it together with the coconut milk.
- Swap the button mushrooms for oyster mushrooms or shimeji if you want a more distinctly Asian character.
- For a vegetarian version, replace the fish sauce with light soy sauce mixed with a little lime juice.
Ingredients
- chicken breast - 400 g
- sweet potato - 300 g
- coconut milk kokosowe z puszki - 400 ml
- chicken or vegetable stock - 800 ml
- lemongrass - 2 stalks
- fresh ginger - 20 g
- garlic - 3 cloves
- fish sauce rybny - 2 tablespoons
- lime juice - 2 tablespoons
- sugar trzcinowy - 1 tablespoon
- red chili pepper - 1 piece
- button mushrooms or oyster mushrooms - 150 g
- oil roślinny - 1 tablespoon
- fresh coriander - 2 tablespoons
- salt
Preparation
- Prepare the ingredients: peel the sweet potato and cut it into cubes of about 1.5 cm; slice the mushrooms or oyster mushrooms. Cut the chicken into thin strips. Finely chop the garlic, ginger and coriander; slice the chili, removing the seeds for a milder version.
- Lightly crush the lemongrass stalks with the handle of a knife to release their aroma, then cut each one into 3–4 pieces.
- Heat the oil in a large pot over medium heat. Add the garlic and ginger and fry for 1–2 minutes, stirring, until they become very fragrant but do not brown.
- Pour in the stock, add the lemongrass and bring to a gentle simmer. Cook for 5 minutes over low heat so the broth takes on the aroma.
- Add the sweet potato and mushrooms. Cook for 10–12 minutes, until the sweet potato is tender – check with a fork, it should slide in easily.
- Add the chicken strips, stir and cook for another 6–8 minutes over low heat, until the meat is completely white inside. Do not cook too long so the chicken doesn’t become dry.
- Pour in the coconut milk, add the fish sauce, sugar and half of the chili slices. Gently heat for 3–4 minutes, without letting it come to a hard boil so the coconut milk doesn’t split.
- Remove the pot from the heat. Take out the pieces of lemongrass (they are not eaten, they’re tough). Add the lime juice, taste and, if needed, season with salt, extra fish sauce or sugar so the flavour is salty, sour and slightly sweet at the same time.
- Serve the hot soup sprinkled with fresh coriander and the remaining chili slices. You can add a wedge of lime to squeeze over each bowl.
Storage
No storage information available for this dish.
After a long, cold day I throw an extra stalk of lemongrass and a few thick slices of ginger into the pot – then this soup works like an edible hot‑water bottle. I often keep a portion without rice and drink it in the evening from a big mug, like a savoury version of hot chocolate.
