Peel and roughly chop the shallot, garlic and half of the galangal. Tear the lime leaves into small pieces. Bruise the lemongrass with the back of a knife.
Place a saucepan over a medium heat and add the sunflower oil, tamarind, garlic, shallot, tomato purée, galangal, lemongrass and lime leaves. Add the water to the pan, bring to the boil and simmer for 20 minutes. Pass through a sieve to obtain the stock.
Finely chop the chilli, removing the seeds if desired. Pick the coriander leaves from the stalks - reserve the leaves for later and finely chop the stalks. Peel and finely chop the remaining galangal. Separate the leaves of the bok choi and rinse under cold water. Slice the spring onions thinly on the angle. Slice the daikon into thin batons, trim the ends from the enoki.
Place a wok over a high heat and add the peanut oil. Once the oil is hot, add the chilli and the galangal. Fry for a minute and then add the coriander stalk, lime juice, bok choi, daikon and enoki. Cook for a further minute and then add the stock to the wok. Bring to the boil, simmer until the vegetables are cooked and then remove from the heat.
Place a couple of bok choi leaves in the bottom of each bowl and add a small handful of fresh coriander leaves. Add a generous ladleful of the stock, ensuring you have a good mixture of vegetables in each bowl. Finish with the remaining coriander, the spring onions and Thai basil.
«Any leftover soup is great served as a salad dressing once cooled.»