Cut tomatoes, red onions, garlic, and bell peppers into large chunks, and put everything in a pot.
The pot needs to be ovenproof, alternatively, you can use a baking tray.
Toss the vegetables in the pot together with oil, oregano, salt, and sugar.
Cook the vegetables in the oven for 30 minutes at 200 degrees Celsius (392 degrees Fahrenheit) (fan).
While the vegetables are roasting, you can cook the pasta for the soup.
After baking, take the pot out of the oven and add water, cream, chopped tomatoes, and tomato paste. Start with 3 dl of water and blend everything well together. If a thinner consistency is desired, add more water.
Bring the soup to a brief boil and serve with pasta, sour cream, and bread.