In a large shaker filled with ice, add the gin, blackcurrant and lime juice. With the lid securely on, vigorously shake for at least 20 seconds. Divide between two low ball glasses filled with ice. Top up with the sparkling wine. Enjoy!
If you have some extra lavender it is fun to make ice cubes with it. They turn out very pretty. Simply place the heads of lavender in the ice cube mold, fill with water and freeze.