This is based on Alton Browns recipe.

4 egg yolks
1/3 cup sugar, plus 1 tablespoon
1 pint whole milk
1 cup heavy cream
1 teaspoon freshly grated nutmeg
4 egg whites

In the bowl of a stand mixer, beat the egg yolks until they lighten in color. Gradually add the 1/3 cup sugar and continue to beat until it is completely dissolved. Add the milk, cream, and nutmeg and stir to combine.

Place the egg whites in the bowl of a stand mixer and whisk to soft peaks (speed 6 for 5 minutes). With the mixer still running gradually add the 1 tablespoon of sugar and beat until stiff peaks form (speed 6 for 3 minutes).

Pour the yolk mixture back into the mixer. Whisk for another 5 minutes. Chill and serve.

It is significantly smoother if you add the rum or bourbon when making the yolk mixture. I don’t bother as I like to share it with the kids.

All the above is basically pointless. You can put all the ingredients in a container of some kind and use a high speed hand mixer. I can’t tell the difference, but mix for a while. So that you can get some foam on the top.