I had one of these during our trip to Washington, DC and it was great. So I took the plunge and bought all the stuff I need to make it.
It calls for equal parts of:
Gin
Maraschino Liqueur
Green Chartreuse (or this substitution Izarra)
Lime Juice
Amarena Cherry for garnish
Combine and store in a jar with a pouring lid. To serve, shake with ice and strain into a cocktail glass and garnish with 2 Amarena cherries on a pick.
Cathy At Home on the River 