A Porto flip is a type of drink which is typically made with brandy, ruby port, and one egg yolk. It's a classic cocktail that use any combination of raw egg (either egg yolk, egg whites, or a whole egg), heavy cream, or simple syrup to create a creamy, froth-topped concoction. The Porto Flip was first recorded by Jerry Thomas in his 1862 book The Bartender’s Guide: How to Mix Drinks.
Pour brandy, port, egg yolk, and ice into a cocktail shaker.
Strain into a chilled coupe glass.
Garnish with nutmeg, if desired.