Prepare a rich vegetable broth. This will require more or less, depending on the thickness of the soup that you prefer. My husband likes very thick soups, but I always cook about 0.5 liters more broth. Cereals and pasta have a not too pleasant feature of swelling, and sometimes on the second day you have to dilute the soup. Well, don’t do it with water. Dilute the broth with water, then interrupt it. The water does not mix with the broth.