Separate 4 eggs, placing yolks in one bowl and whites in another
Whisk 1/2 cup sugar into the yolks until smooth and pale
Stir in 2 cups milk, 1 cup heavy cream, 1 teaspoon vanilla extract, and a pinch of nutmeg
Add 1/2 to 1 cup bourbon, rum, or brandy if desired
Beat the egg whites until soft peaks form
Fold the beaten egg whites into the mixture
Chill for at least 1 hour
Serve cold with grated nutmeg on top