Ingredients (Serves 4 - adjust quantities for more people))

2 skinless chicken breasts (6 oz/175 g each)

2 pints (1.2 litres) chicken stock

a small bunch of coriander leaves (1/2 oz/10 g)

2 small red bird's eye chillies

1 stalk of lemon grass, roughly chopped

a small piece (1 inch/2.5 cm) of ginger, peeled and sliced

2 medium, ripe tomatoes

3 spring onions, trimmed and finely sliced

(including the green parts)

juice of a large lime (about 2 tablespoons)

1 tablespoon tamarind purée

1 tablespoon Thai fish sauce

2 oz (50 g) snow peas, (mange tout) cut in half

2 oz (50 g) fresh, shelled peas

Method

Pick all the coriander leaves off the stalks and then cut 1 of the chillies in half lengthways and deseed it.

Put the chicken stock into a large saucepan and add the coriander stalks, halved chilli, lemon grass and ginger. Bring the mixture to the boil, give everything a stir, then cover and leave to simmer very gently for 15 minutes to allow the Thai flavours to infuse the stock.

(You can make this stock in advance but add the rest of the ingredients shortly before serving.)

Place the tomatoes in a bowl and pour boiling water over them and leave them for 1 minute before draining.

Skin the tomatoes and cut each one into quarters, then remove the seeds and cut each quarter into three lengthways, so you end up with thin slices.

Cut each chicken breast in half widthways and then slice each half into five or six long thin strips and then slice each of these in half lengthways so you end up with thin slivers of chicken.

Strain the stock into a colander set over a bowl and discard the flavourings.

Return the stock to the pan and when it is back to simmering point, stir in the thin slivers of chicken, and half of the spring onions.

Stir and then cover again and leave the chicken to poach gently for 5 minutes or until it is cooked through. Meanwhile, trim and halve the remaining chilli, remove the seeds, and then finely slice it, making sure you wash your hands afterwards.

Add the peas, snow peas, sliced chilli, fish sauce, tamarind and lime juice to the soup, stir and gently simmer for 2-3 minutes or until the peas are just tender but still retain their bite.

Stir the slices of tomato in at the last minute and then divide the coriander leaves among four deep bowls.

Ladle the hot soup on top, sprinkle with the remaining spring onions and serve immediately.