Melt the butter in a large saucepan over medium heat. Fry the onion in butter until soft, about 5 minutes. Add the parsnips, garlic and curry powder, and fry for a couple of minutes to release the flavours.
Boil the water in the kettle and mix with stock cube in a separate jug. Add to pan and stir well.
Simmer for 15 mins until carrots or parsnips are soft and easy to break with a wooden spoon.
Take off the heat and blend with hand mixer or food processor.
Stir in the cream and warm through.
Season to taste and garnish with the chilli flakes or paprika.