Pour all ingredients in mixing glass and stir for 10 seconds. Strain into an old fashioned glass pouring over a zesty ice ball.
To make the zesty ice ball, make a long, thin orange peel and place at the bottom of a plastic ice ball mould. Fill mould with hot water and place it in freezer for minimum 8 hours. Remove frozen ice ball gently from mould and place in the cocktail glass. You can get the ice moulds at Muji.