This original cocktail was originally submitted to the Louis 649 "Anyone Can Be a Mixologist" Competition (read the recap) in April 2010. The Cinquecento is available commercially on the Louis 649 menu as well as barkeeper extraordinaire Mal Spence's cocktail tome at the Blythswood Square Hotel bar in Glasgow, Scotland. You can also ask for it at great cocktail bars such as Clover Club in Brooklyn.
Read the full Ardent Spirits review here.
Gaz Regan is the author of many cocktail and drinks related books including the must have Joy of Mixology and Gin Compendium. He is also the brains behind Regan's Orange Bitters and is regarded as a pillar of the cocktail community.