- Finely chop the onion, garlic, chilli and ginger.
- Add the oil to a pan big enough to make the soup in. Add the finely chopped vegetables and spices. Stir into the oil until coated.
- Add curry paste and butter, then stir well.
- Cut zucchini and spring onion into chunks and fry with the butter and spices.
- Pour in the coconut milk, double cream and the the sugar dissolved in the juice of the limes.
- Bring to the boil and allow to simmer.
- Cut the cod into cubes.
- Add the cubes of cod to the soup and cook for 10 minutes.
Pour into bowls and top with mango, sliced spring onion and chopped coriander.