Kaeng som (sour fish curry)

Instructions

1. Cut the fish into large chunks, the green beans into 4 cm lengths and the squash into cubes.
2. Bring the water to the boil in a saucepan and whisk the red curry paste into it.
3. Add the tamarind pulp, fish sauce, palm sugar and lime leaves, then let it simmer for 5 minutes.
4. Add the squash and green beans and cook for 5 minutes.
5. Slide the fish into the broth and poach for 3 to 4 minutes without stirring, until it flakes apart.
6. Taste and adjust: the soup should be clearly sour, lightly salty and slightly sweet.
7. Sprinkle with basil and serve hot with rice.