- 6½ cups chicken stock
- 1 heaping tablespoon torn yam hot and sour paste
- 4 kaffir lime leaves, finely chopped, optional
- 1 stick lemongrass, tender inner part only, roughly chopped
- Juice of 1 lime
- 4 tablespoons fish sauce (nam pla)
- 2–3 small jalapenos or fresh red or green chillies, finely chopped
- 1 teaspoon sugar
- 1½ cups plus 2 tablespoons straw or button mushrooms, halved or quartered according to size
- 1 pound 2 ounces peeled raw shrimp, thawed if frozen
- 5 small scallions, cut into short lengths and then into strips
- Small bunch cilantro, chopped
- Heat the stock and torn yam paste in a decent-sized saucepan with the lime leaves, lemongrass, lime juice, fish sauce, chillies and sugar.
- Bring to the boil, add the mushrooms and simmer for a couple of minutes, then add the shrimp and scallions and cook for a further 2–3 minutes, or until the shrimp are cooked but still tender.
- Sprinkle with a little cilantro and put more on the table for people to add themselves as they want.