Gaeng bong (vegetable soup with fish broth)

Instructions

1. Bring the water to a boil with the fish, then simmer for 10 minutes to make a fragrant broth.
2. Pound the garlic, shallots and chillies in a mortar, then add them to the broth with the fish sauce.
3. Add the squash cut into cubes and cook for 8 minutes at a simmer.
4. Stir in the diluted tamarind paste, the beans, the chopped courgettes and the chopped tomatoes.
5. Continue cooking for 5 minutes, adjust the salt and tamarind, then scatter with Thai basil and serve with sticky rice.