Combine the Irish whiskey, dry vermouth and green Chartreuse in a mixing glass.
Add ice and stir for 25 seconds until well chilled.
Strain into a chilled coupe.
Garnish with a single mint leaf floated on the surface.
An American classic from the early 1900s, usually printed with a bar spoon of green crème de menthe alongside the Chartreuse. Dropping the crème de menthe removes the sweetness and the novelty-green colour and leaves a genuinely good aperitif.
My Bar Shelf läser ditt skåp och visar varje cocktail du kan göra av det du redan har - inklusive Shamrock.