Fill a rocks glass to the top with ice cubes
Place 5 red basil leaves, 2 grapefruit wedges into a shaker and muddle
Pour in 0.75 oz of sugar syrup, 0.5 oz of grapefruit liqueur and 1.5 oz of genever
Fill the shaker with ice cubes and shake
Finely strain into the rocks glass
Garnish with red basil leaves