Stone the plums and cut the flesh into small pieces. Peel the ginger and grate finely.
Bring the plums and ginger with the remaining ingredients (without salt) to the boil in the saucepan over medium heat while stirring, fish out the star anise and pick it up, puree with the magic wand and then boil for 3 minutes while stirring.
Now season to taste with salt and pour it boiling hot into glasses or ketchup bottles with twist-off lids. Put a star anise in each glass.