This simple little soup is beautiful and delicious. The main trick is to cut the ingredients into ultratiny dice—confetti, if you will. That way, the vegetables cook quite rapidly and contribute their flavor to the soup, making essentially a sort of quick, very fresh-tasting vegetable stock. If you do happen to have a little homemade chicken stock on hand, use it instead of water, but it’s not necessary. I often make just enough for my own lunch, and it really only takes a handful of chopped vegetables. I begin with a finely diced onion and ad-lib from there, depending on the season.