Curried smoked haddock soup

1) Heat the oil gently in a large saucepan, add all the ingredients except the haddock and the stock.
2) Sweat everything gently for 10-15 minutes, stirring to ensure ingredients are coated in the oil. Season to taste.
3) Add 1litre of the stock, bring up to the boil then turn down to a low simmer for 10 minutes
4) Add the haddock and continue simmering for another 10 minutes or until the vegetables are tender.
5) Meanwhile put the sunflower seeds into a dry frying pan and toast for a few minutes until browned.
6) Once the soup is ready, allow to cool then transfer to a blender and liquidise in batches.
7) Return to the pan and thin down with reserved stock if necessary. Check seasoning.
8) Reheat and serve with toasted sunflower seeds on top.