Preheat the oven to 225˚ C. (400˚F) Clean and cut the pumpkin and put the pieces onto a baking tray with the cinnamon, cloves, chili powder and salt. Toss to combine and sprinkle with olive oil. Put into the oven for about 12 minutes.
Heat a large soup pan over medium heat with some oil and add the onions, garlic, chili pepper, carrots and bell pepper and bake for about 5 minutes.
Add the roasted pumpkin into the pan, toss for a bit and than add the stock in and let it simmer for about 30 minutes.
Use a stick blender to puree the soup and add salt and pepper if needed.
Add the yogurt to the soup and spoon it through before serving.