Pink Lemon Tiger

Softly pound a stalk of lemongrass to release the aroma, cut into 3-4 cm long pieces and place in a shaker. Cut a slice from the quartered grapefruit and set aside for later garnish. Cut off the peel from the rest, add the pulp to the lemongrass in the shaker and muddle lightly. Then add ice and shake. Double strain in a tumbler and pour in Goldberg Tonic Water. Finally, perfume the glass with the essential oils of a grapefruit zest, add a few grains of pink pepper to the glass and garnish with the remaining slice of grapefruit.