Slice the plums, cover with lemon juice and thyme syrup and let steep until the plum juice comes out.
Put a few extra drops of lemon juice in a glass. Add ice cubes and about three slices of plum. Drizzle with a little thyme syrup if necessary. Fill the glass with your favorite Prosecco and serve.
Tip: You can easily make the syrup yourself. To do this, reduce the water and sugar in a ratio of 1: 1 until the mixture is slightly thickened. Add a few sprigs of thyme and let it steep.