Tomato soup is only worth making for the few weeks of summer when the sun has had a chance to give the fruit some flavour. Even then, tomato is so acid that you need to add other ingredients to temper this. Soup made only of tomatoes is not very good.
For 4 people, an onion, a carrot, a medium potato and 1 or 2celery stalks, olive oil. up to a kilo (2