First, add Englishman Gin, Aperol, Grapefruit Juice and simple syrup to a shaker. Add ice to the shaker and shake for 10-15 seconds.
Line a glass with grapefruit slices and fill it with ice to keep them in place.
Strain the contents of the shaker into the glass and top with Pink Grapefruit Soda.
Garnish with a sprig of rosemary and enjoy!