If you haven’t made it in advance, follow the instructions above to create fresh cucumber juice.

In a glass filled with ice, combine the cucumber juice and elderflower liqueur (or syrup).

Slowly pour the Prosecco (or non-alcoholic alternative) over the mixture to preserve its bubbles.

Add the club soda to give the final touch of fizz.

Garnish with a slice of cucumber or a sprig of mint.