Place a slice of ginger root into a shaker and muddle
Pour in 1 oz of lime juice, 0.75 oz of sugar syrup and 1.5 oz of gin
Fill the shaker with ice cubes and shake
Finely strain into a chilled sour glass
Soak a sugar cube with blue curacao liqueur, so that the sugar cube becomes bright blue
Place an absinthe spoon with sugar cube on top of the sour glass
Pour club soda through the sugar to the top and stir gently