The key to preventing dumplings from falling apart is being careful not to overcook them. Lower the heat to medium-low so that the soup is barely simmering then drop the dumplings on top one at a time. Cook the soup with the lid on for 10 minutes then cut a dumpling open to see if they are cooked through. If the dumpling is still raw in the middle add 2-3 more minutes of cooking time then check again. Immediately remove the pan from the heat once the dumplings are done.