Fill a cocktail shaker with ice. Add the gin, lemon juice, and simple syrup. Cover and shake until mixed and chilled, about 30 seconds. (In general, the drink is ready by the time the shaker mists up.) Strain into a chilled Champagne coupe or flute. Top the drink with Champagne and serve with an edible flower or fresh currants.

Put the sugar and water in a small saucepan. Cook over low heat, stirring, until the sugar dissolves. Alternatively, heat the sugar-water mixture in the microwave. Store the syrup in a sealed container in the refrigerator for up to 1 month.

Yield: about 1 1/2 cups