Rum or brandy,
Beat egg whites until moderately stiff (soft peaks). Whip the heavy cream & fold in the egg whites, then fold into the yolk mixture in a large punch bowl. Garnish with grated nutmeg.
In a large bowl combine 12 egg yolks and 1 cup sugar; beat till lemon colored and thick. Slowly add 2 cups light cream. Add 1 liter rum/brandy at this point if desired. Beat to blend well and chill 1 hour or more to allow eggs to mellow.
This eggnog is very thick and rich; you almost need a spoon to 'eat' it!