1. Peel and core the squash, cutting it into 1" cubes. Peel and roughly chop the onions and peel the garlic.
2. Place all the vegetables into a roasting dish and cook them in a hot oven 200°C / 400°F / gas mark 6 for 20-30 minutes until they begin to brown. Scatter over the crushed cumin seeds and roast for a further five minutes.
3. Scrape the contents of the pan, including any bits that have stuck, into a large saucepan and add the stock and coconut milk and a good pinch or salt and pepper.
4. Cook until the squash is meltingly tender then blitz in a blender or food processor until smooth.
5. Return the soup to the heat and taste, re-seasoning as necessary.
6. Serve the soup hot with some coriander leaves and pomegranate seeds scattered on top to resemble holly.