Start by making the rosemary syrup. Pour the water into a saucepan, add the sugar and then the rosemary. Cook over medium heat until the sugar is completely melted and the liquid begins to shrink (about 10 minutes).
Turn off the heat and let it cool, leaving the rosemary into the saucepan. When the syrup is cold, remove the rosemary and transfer it into a clean glass container with a cap. You can keep the rosemary syrup in the fridge for up to two weeks.
Peel the peaches and cut them into pieces. Put them on a baking sheet covered with parchment paper. Add the sugar and cook in the oven at 200°C in static mode for about 10 minutes or until they are soft.
Remove the baking sheet from the oven, transfer the peaches into a blender and mash them. Sift the obtained purée with a sieve and put it into a bowl. Let it cool.
Make the cocktail. Pour 80 ml of rosemary syrup into the bowl with the peach purée and mix well. Take two tall glasses and fill them with ice. Divide the rosemary peach purée between the two glasses and add the cold Rocca dei Forti Prosecco DOC. Mix with a long cocktail spoon, garnish with the rosemary and serve immediately.
FOR THE ROSEMARY SYRUP
125 ml of water
100 g of granulated sugar
2 springs of rosemary
FOR 2 COCKTAILS
80 ml of rosemary syrup
3 nectarines
1 tablespoon of brown sugar
Rocca dei Forti Prosecco DOC
ice
springs of rosemary to garnish