If you don't want to try thick, I mean thick eggnog, then this is not your "go to" recipe. Evidentally, the eggnog of yesteryear was more akin to Zabaglione than a drink, still you can cut the whipped egg whites by half and have a more "drinkable" version. Archie was the uncle of a woman I used to work with and when he gave me this recipe, I promised I would always give him credit for it. He used whisky in the original version, but said I could use brandy if I so desired.
12 jumbo eggs
2C brandy (or you can use 2/3 brandy 1/3 rum)
1/2C boiling water
2C heavy whipping cream
2C half & half
Separate the eggs and whip the eggwhites to a stiff peak, then set aside.
Whip egg yolks until very smooth, then add sugar and salt and whip well until they are very fluffy.
Slowly pour in the alcohol and keep whipping. When all these ingredients are blended, add the boiling water, cream and half & half, one at a time while you continue to whip, then fold in the egg whites. I would suggest reserving half of the egg whites until the first half are folded in, to better judge a sufficient amount.