Peel, slice and remove the stones from the plums.
Remove the leaves from 6 small sprigs and add to the plum pieces.
Blend until smooth using either a blender or immersion blender.
Taste - the thyme flavour should be present but not overpowering; add the leaves from another one or two thyme sprigs if necessary and blend again briefly.
Strain the puree through a sieve to remove the lumps and bits.
Pour approx 45ml (one jigger or 3 tbsp) of the plum puree into the bottom of a glass.
Gently and slowly pour the wine over the top; do this slowly and carefully as it will fizz. Stir gently.
Serve and enjoy immediately.