When the broth starts to boil again, and the turnip greens reduced their volume, add the beans and let cook while we chop the potatoes.
Add the potatoes and cook until the beans are tender.
Let stand 24 hours.
The next day we give it a boil before serving.
Video
Notes
As we are using the broth that we have kept (we can freeze it if we are not going to use it immediately) after cooking a Galician stew, the amount of salt provided by the meats of the stew should be enough. However, is best to taste the broth and add salt ir required.