Pinakbet is a Filipino stew that often includes kalabasa or other squash and long beans. As this version shows, you can use a range of other vegetables too. Cutting the vegetables into even pieces helps ensure even cooking. Put longer-cooking vegetables in the pot first, adding quicker-cooking ones later. Fermented shrimp paste (available in Asian grocery stores) adds distinctive flavor to the soup; results will be good without the paste if you are unable to find it.