You take the raw veggies you're going to use in the soup, chop 'em, mix 'em together, and split 'em into thirds.
The first third you put into the soup stock (V8, tomato juice, bouillon) and start at a slow boil. My favorite soup stock is low-sodium V8 with chicken bouillon powder.
The second third you put in a skillet or wok and stir-fry/grill/fry until you get grill marks. The grill marks keep these veggies crunchy even when they're in the stock.
The third third you add raw. If you're making the soup to store, it's even better if you add the raw portion after the soup is cold.
The "Tres Tercios" triples the flavors of the ingredients you add, puts some crunchy texture in the soup, and makes sure the soup has some substance after you freeze it and reheat it.