Serious Eats: Recipes
This Don the Beachcomber classic was created around 1941. As Paul Clarke notes on his blog, Cocktail Chronicles, the key is the combination of Angostura bitters and Pernod:
Both are used in minute doses, so you don't actually taste their flavor up front, but Angostura does its deep, spicy thing in the glass while the Pernod takes its mildly sweet anise-ey flavor and spreads it out to the far corners of the drink, so you don't actually taste anise, but you know something is in there that's rounding the edges of all the other flavors. I'd go even further and say that Don's use of this bitters-pastis one-two punch is the missing link between the old-school classic cocktails of the Gilded Age and beyond, and the mid-century Tiki movement that Don helped launch.
You're looking for a drink that's mixed but not totally blended into a smoothie. It's ok if the ice has a little texture; this isn't a Slurpee.