Most people don't know escarole from escargot, but that's okay. Just know that escarole is a delicious leafy green vegetable that's high in vitamin C. Leeks, which resemble large scallions, have a slightly oniony flavor. Here, I've used both in a main-meal soup that is filling and nutritious.
Try sprinkling a little smoked paprika over the soup before adding the cheese-it will give a sweet, smoky, slightly spicy flavor.