Tom yum, the classic hot and sour soup from Thailand is the perfect thing to eat when you feel as if you've overdone it with stodgy, rich or greasy food and are craving something light, cleansing and restorative.
The broth is bursting with aromatic flavours: heat from the chillies, a sour note from the tamarind, saltiness from the fish sauce, a zesty edge from the lemongrass. It is quick and simple to make, packed with healthy ingredients and surprisingly filling. Depending on what is available, you can add an array of different vegetables: asparagus, mange tout, bok choi and green beans would all work well. Because the vegetables are only cooked briefly, they retain their nutrients and by poaching the prawns (a good source of low-fat protein) rather than frying them, fat content is kept to a minimum. The prawns can be replaced with white fish, skinless chicken breast or tofu; be aware cooking times will vary.
Tom Yum soup
For the paste
1 garlic clove, peeled and chopped
1 lemongrass stalk, chopped
2cm piece galangal (or ginger), peeled and chopped
2 shallots, peeled and chopped
4 lime leaves
2 tomatoes, deseeded and chopped
1 small bunch coriander, stems only (reserve the leaves for later)
1-2 bird's eye chillies (to taste), deseeded and chopped
25g palm (or brown) sugar
2 tbsp vegetable oil
For the soup
1 tbsp vegetable oil
1 litre fish or vegetable stock
1 tbsp tamarind paste
1 tbsp fish sauce
8 large raw prawns, shelled and deveined
head broccoli, cut into small florets
50g oyster mushrooms, torn into pieces
6 pieces baby corn, roughly chopped
2 lime leaves, shredded
juice of lime
Tip all the ingredients for the paste into a food processor, season with salt and blend until smooth.
Heat a tablespoon of vegetable oil in a large wok or saucepan over a medium heat, add the paste and cook for 2-3 minutes, until the spices start to smell really aromatic.
Pour over the stock, stir well and bring to the boil briefly. Reduce the heat and simmer for 10 minutes. Dissolve the tamarind paste in 5 tablespoons of hot water and add to the stock, along with the fish sauce.
Slice the prawns in half and add to the pan, followed by the broccoli, mushrooms and baby corn. Simmer for 3-4 minutes, or until the prawns are cooked through.
Pour the soup into two serving bowls and garnish with the reserved coriander leaves, the shredded lime leaves and a splash of lime juice.