Cut up the pumpkin and carrots and transfer to a roasting tin, season with allspice, thyme, cinnamon, salt and pepper and drizzle a little cooking oil and mix. Roast the root vegetables for about 40 mins (or until very tender) at 180 Deg C.
In a deep pot, add buter and 1 tbsp oil and sweat off the onion and garlic. Add the roasted vegetables in and add the chicken (or veg) stock and bring to a simmer.
Using a imersion blender, slowly blender the vegetables and stock until a smooth soup.
Add Cream (as desired amount) until smooth and creamy. Do not boil!