Preheat the oven to 200 degrees Celsius/ 400 degrees Fahrenheit. Line a large baking tray with parchment paper.
Peel the butternut squash, remove the seeds and chop it roughly, about 2 cm/1-inch large pieces. Deseed and quarter the pepper. Peel and slice the carrots rather thickly. Chop the onions roughly. Peel the garlic cloves but leave them whole.
Place all the vegetables on the prepared baking tray. Pour the olive oil over them and sprinkle them with paprika, salt, and pepper. Rub well with the hands to coat all over.
Roast for about 30-40 minutes, tossing halfway, or until the vegetables are tender.
Place them in a soup pot, add about half of the stock. Blend until smooth and then add the remaining stock and the cream. Alternatively, blend in a blender with about half of the stock and then pour into a soup pot, add the remaining stock and the cream.
Bring to a boil, turn the heat down and simmer for 15 minutes. Adjust the taste with salt, pepper, lemon juice, sugar, and chili flakes.
Sprinkle with parsley before serving.