The Chelsea Collins Royale is a glamorous cocktail that combines gin, elderflower liqueur, lemon juice, and champagne. It is a luxurious and bubbly drink that is perfect for celebrating special occasions in Chelsea. The gin and elderflower liqueur create a floral and fragrant flavor, while the lemon juice adds a tangy twist. The champagne gives it a touch of elegance and effervescence, making it a truly indulgent cocktail to enjoy in the upscale atmosphere of Chelsea.