Preheat the oven to 180°C, fan 160°C, gas mark 4.
Chop the pieces of prepared butternut squash into smaller bitesize chunks and place in a roasting tin. Drizzle with half the oil, season well and roast in the oven for 35 minutes.
About 10 minutes before the end of the squash's cooking time, heat the rest of the oil in a wok over a medium heat. Add the green pepper and onion, and stir-fry for 3-4 minutes.
Add the raw king prawns and stir-fry for 2 minutes, until just pink, then add the roasted squash.
Add the Indian stir-through creamy coconut and cook for a further 1 minute until the sauce is piping hot. Garnish with coriander and serve with steamed white rice.