Preheat the oven to 200`c. Peel the pumpkin and sweet potato and chop them into large chunks. Peel the onion into quarter wedges. Place the vegetables onto a large baking tray lined with baking paper or foil. Drizzle the vegetables with olive oil and sprinkle over the cinnamon and nutmeg. Roast the vegetables for about 45 minutes until they are golden and cooked through. Bring 1 litre of vegetables or chicken soup to the boil. Add the roasted vegetables to the stick and use a stick blender to puree the soup. If soup is a bit thick, add some more stock or hot water to thin out the soup. Heat the soup until it gently simmering and taste for seasoning.