Punch Lalla Rookh

A two-line finish to a base recipe: the whole thing hinges on the texture of the cream at the moment the rum goes in.

• French ice creamIn books of this period that means a cooked custard base -- egg yolks, sugar and scalded cream or milk, stirred over heat until it coats a spoon, then chilled and churned. It is not a no-cook cream, and the yolks should reach about 175F before chilling.
• WineglassfulRoughly 2 fluid ounces, a scant quarter cup. Nineteenth-century wineglasses were small; do not read it as a modern stemmed glass.
• Add the rum lastAlcohol depresses the freezing point, so any rum churned in from the start will keep the mixture slack. Freeze first, then beat the rum in quickly and serve, or the punch slumps into a milkshake.
• The target textureThick frozen cream, not solid -- soft-serve consistency, still pourable off a spoon. On a modern machine that is the point at which you would normally transfer to the freezer to harden, not after.
• Jamaica rumA dark, high-ester pot-still rum. The strong molasses character is the whole point of the drink; a light or spiced rum gives something flat and sweet.
• ServingSmall glasses with a spoon, treated as a frozen punch course rather than dessert. The recipe gives no quantity for the ice cream, so the yield depends entirely on the size of the batch you have frozen.
• Holding itThe rum keeps the mixture softer than plain ice cream would be, so it is best beaten in and served at once rather than held.