Cut the vanilla bean in half, scrape out the seeds and add them to the pot. Also add the bean halves, so they can boil with the plums for a while (hint: since the mix gets quite dark it might take a while to fumble them out later on. Relax, breathe, contemplate until you find them – a perfect meditation technique!).
Add all other ingredients except the couverture and stir. Make sure the spice bag is down under and not on the surface. Cover with a lid.
Let it rest for 24 hours, or at least overnight and then some. Do not touch it during that time.
Then you can open and stir it and let it rest for another while.
And now: cooking time! Heat on medium, then let boil softly for some hours with the lid on, sometimes stirring.