Sauté the onion, carrots and celery in the oil for ten minutes. Add the tomato puree and stir for a minute. Add the tomatoes, the sugar and a little black pepper and sauté. Add the bay leaves and stir. Allow the tomatoes to stew over low heat for ten minutes. Add stock and mix well. Bring the mixture to a boil and then reduce the flame. Cook for 20 minutes, stirring occasionally. Remove and discard the bay leaves. Puree the soup into a blender until smooth. Serve and enjoy.