You need a shaker, bar strainer and a pre-cooled champagne glass.
Put the ice cubes in the upper part of the shaker. Add the lemon juice, blue curacao, vodka and lime juice. Close the shaker and shake everything vigorously for about 8 seconds. Strain the mixture through the strainer into the pre-chilled glass and fill up with champagne as required. Carefully pour the cocktail cherry into the glass and serve the drink immediately.