How to Make It
In a blender, puree the peaches until smooth. Strain the puree into a glass measuring cup; you should have 1 1/2 cups.
In a cocktail shaker, muddle the lemon verbena leaves with the ice. Add the peach puree and shake well. Strain the puree into the measuring cup. Pour the peach puree into Champagne flutes, top with the Prosecco and serve right away.