Lalla rookh is a dessert, and a cocktail, popular in restaurants from the late 19th to early 20th century in the United States. In every version, it combines a spirit with ice cream in individual serving glasses. It is now a fairly exotic and unknown recipe, though some bartenders with an interest in historic cocktails have written about it.
The name of the dishes is derived from a well-known poem by Irish poet Thomas Moore written in 1817, describing a fictional Persian princess by the same name; that name, in turn, is derived from the Persian expression "laleh rox" (or "rukh"), meaning "tulip-cheeked", which is commonly used in Persian poetry.
In the 1895 cookbook Modern American Drinks, a recipe for a lalla rookh cocktail is given:
Lalla Rookh cocktail
one pony vanilla cordial
one half jigger brandy
half a jigger rum
a small spoonful fine sugar
a whiskey glass full cream
To a mixing glass half full of fine ice, add all ingredients. Shake well and strain into a long thin bar glass.
In the 1919 The Hotel St. Francis Cook Book, a recipe for a rum-soaked lalla rookh dessert is given:
Lalla Rookh (dessert)
one quart vanilla ice cream
one pony Jamaica rum, plus extra for serving
To a quart of vanilla ice cream add a pony of Jamaica rum, and mix well. Serve flat in glasses with a little rum on top.