Lightly spiced carrot soup

1 tbsp vegetable oil, 1 onion, finely chopped, 1 garlic clove, chopped, knob of fresh root ginger, grated, 1 red chilli, deseeded and chopped, 1 tsp mild curry powder, plus extra, 1kg carrots, trimmed and sliced, 2 lemongrass stalks, bashed, 2 strips orange zest, 400g can coconut milk, 700ml vegetable stock

Heat the oil in a large pan with a lid. Tip in the onion, garlic, ginger and chilli, then cook for 3-5 mins until soft. Stir in the curry powder, followed by the carrots, lemongrass and zest, then cover and cook over a low heat for 10 mins more.
Give the coconut milk can a shake, then pour most of it into the pan along with the vegetable stock. Bring to the boil, then turn down and simmer for 15 mins until the carrots are really soft. Remove the lemongrass and orange zest, then use a stick blender or food processor to whizz until smooth. Ladle into bowls and top with a swirl of reserved coconut milk and an extra sprinkling of curry powder, if you like.