Photograph: Jonathan Gregson
Heat the oil in a large pan and gently fry the onion, garlic and chopped chilli for 5-7 minutes, until softened. Stir in the turmeric and curry paste and fry for a further minute.
Add the butternut squash and coconut milk, bring to the boil, then simmer for 15 minutes.
Stir in the prawns and lime juice, and simmer for a couple of minutes until the prawns are cooked. Check the seasoning. Add most of the coriander leaves (discard the stalks) and serve topped with the rest and the slices of chilli. Serve with basmati rice.