Preheat the oven to 200ºC, and spray a baking tray with low-calorie cooking spray.
Add the pumpkin to the baking tray and sprinkle over the Cajun spice mix and smoked paprika. Pop in the oven for 20 minutes. After 20 minutes, give the tray a shake, then add the onion, garlic, and red chilli. Cook for a further 20 minutes.
Add the roasted vegetables to a large saucepan. Then add the stock cube to the boiling water, and pour into the pan, along with the coconut milk. Set the pan on a medium heat, and bring to the boil. Lower the heat and simmer for 15 minutes.
Using a stick blender, blitz the soup until smooth. Add a little water until the soup is your desired consistency, then season with salt and pepper to taste. Serve with some pumpkin seeds and a sprinkle of smoked paprika.