A Sweet Manhattan served on-the-rocks with added herbal complexity and an all-important splash and dash or two of New Orleans bitters.
Driven by comments...
I am just back from visiting New Orleans and had this cocktail in several bars (tho the Carousel Bar was not one of them). One was served up in a chilled cocktail glass, at the other two it was on the rocks, and I've seen recipes from several sources differ on that. I prefer up vs. on the rocks - but is there a "correct" approach, or is it just personal preference? Either way it's a fantastic cocktail, one of my new favs...