Bring water to a boil in a medium sized pot. Cut the skin of the peaches a few times and place into boiling water for about a minute. Rinse under cold water and peel of the skin.
Remove the stone and cut into small chunks. Blitz to get a smooth fruit puree.
Store in the fridge until needed.
Fill 4 champagne flutes with prosecco and add about 1-2 tablespoon of fruit puree to each glass. Because the puree is much heavier than the champagne it is easier to mix this way round.