Combine milk, half and half, and sugar in a large bowl or container.

Stir until the sugar is completely dissolved.

Separate the eggs, placing the yolks in a separate bowl and the whites in another.

Beat the egg yolks until they are well combined and slightly lightened in color.

Using an electric mixer on low speed, gradually add the brandy to the egg yolks, mixing very slowly to avoid curdling.

In the same manner, slowly add the rum and bourbon to the yolk mixture, continuing to mix on low speed.

Pour the milk-sugar mixture into the yolk-liquor mixture and stir to combine thoroughly.

In a clean bowl, beat the egg whites until they form soft peaks.

In another bowl, beat the whipping cream until it is firm but not too stiff.

Gently fold the whipped cream into the liquor mixture.

Then, gently fold in the beaten egg whites, being careful not to deflate the mixture.

Grate a small amount of fresh nutmeg over the top.

Cover the eggnog and chill in the refrigerator overnight (approximately 24 hours) to allow the flavors to meld.

Before serving, stir or shake the eggnog to ensure it is well mixed.