This holiday drink, a variation on eggnog made with brandy, was first invented by a British sportswriter and journalist named Pierce Egan in the 1820s; it's named after two characters in his best-known satirical work. If you make the recipe in quantity, use a punch bowl and cups. Punch sets from the 1960s with “Tom & Jerry” written on them sometimes turn up at antiques shops and flea markets.
Note: Use only fresh eggs from a reliable source in this recipe. If contamination is a concern, look for pasteurized eggs at your grocery store.
Beat egg yolks, sugar, and allspice at high speed with an electric mixer until thick and lemon-colored. Blend in rum and brandy.
In separate mixing bowl, beat egg whites and cream of tartar until they form firm (but not dry) peaks. Fold in yolk mixture. Spoon ½ cup of the mixture into four warmed 8-ounce mugs. Fill each with ⅓ cup hot milk. Grate a bit of nutmeg on top and serve immediately.