To make ribollita, canned beans can be used (healthy tip: if you rinse well your canned beans you can decrease the salt in them by 50%). However, it is yummier and healthier to use your own simmered beans. And on a wintery day in Chicago, bubbling beans is a great zen activity, it feels satisfying. Once your beans are cooked, you can put them in a tupperware, or a baggie and freeze them until you are ready to make soup.
Ribolitta can be made with any vegetables you have on hand. I give you the recipe for what I used, but feel free to use what is on hand. Any fresh vegetables will make a delicious soup. Although greens of some sort are a necessity.