Preheat the oven to 200°C (fan) / 400°F / Gas Mark 6.
Cut the pumpkin in half. Removed the inners and seeds, and set aside to roast the seeds. Cut the remaining pumpkin into inch strips, and lay on a roasting tray.
Roast for 25 minutes or until the pumpkin is soft. Remove from the oven and allow to cool for a couple of minutes.
Slice off the pumpkin skins, and add to your skillet along with the onion. Cook down for 5 minutes.
Add the stock, tomato purée, coconut milk and blitz until completely smooth. Taste and adjust seasoning as required. Serve immediately.