Add all the ingredients into a shaker with ice and shake.
Double-strain into a Champagne flute.
Top off with prosecco.
Garnish with a lemon twist.
*Rose-geranium-infused beet juice: Slowly heat 1 qt beet juice, 1 cup sugar and 1 to 1 ½ cups dried rose geranium slowly in saucepan on low heat. Simmer for 10 minutes so the sugar is dissolved and the geranium can steep. Let cool and strain.