For perfect vegetable soup base, whether it is chicken noodle, a minestrone, or some other soup start with your diced veggies, such as diced carrots, onions, peppers and tomatoes, and saute them in oil or butter before you add any liquid. This brings out the taste and caramelizes the sugars. This will lead to a far more flavorful soup! Yummy. This is true for hot soups, as well as those served cold.