In a non-stick saucepan, over medium heat, combine heavy cream, unsweetened almond milk, nutmeg.
Stir constantly until it forms a light simmer and simmer for 5-6 minutes
Remove the saucepan from the heat while you prepare the egg yolk mixture.
Separate egg yolks and egg whites. Set egg whites aside - you won't have to use them, see optional step if you want to add them for an extra fluffy texture.
Using an electric beater, beat the egg yolks and erythritol on high speed for 40-60 seconds, in a medium bowl until light, creamy and lighter in color.
Add large scoops of the hot milk very slowly into the egg mixture, whisking vigorously at the same time to avoid curdling the eggs. This step is called tempering the eggs.
Repeat adding a large spoonful of milk one at a time until eggs are temper. Once half of the hot milk has been added to the egg bowl, pour the mixture back to the saucepan.
Return the saucepan over low-medium heat, stirring constantly for 6-8 minutes. Don't boil, it should stay around 160°F/70°C and stir constantly until the mixture gently thickened and cover the back of the spoon.
Remove from heat and sieve onto a large bowl.
Stir in vanilla extract and spirit of choice if used.
Cool it down for 15 minutes at room temperature, give a quick stir, and cover the bowl before transferring to the refrigerator to chill for 6-8 hours.
The eggnog thickens in the fridge. Stir before serving and if too thick to your liking, add 2-3 extra tablespoons of almond milk and whisk to combine
This recipe serves 8 glasses, 1/2 cup each. Serve each glass with a sprinkle of cinnamon or nutmeg, a cinnamon stick, and a dollop of fresh unsweetened whipped cream if desired.
Store in a sealed container in the fridge for up to 1 week
Optional - add egg-whites for an airy fluffy drink
Just before serving, add the reserved egg white in a stand mixer and beat until stiff peak form
Transfer the egg whites to the chilled eggnog bowl and fold, stir until combined. This makes the drink extra frothy, some of the egg white will float on top of the drink too and that's ok and delicious
Notes
What to do with egg whites? If you don't want to add the egg whites in this recipe you can make keto cloud bread with them or my keto French floating island dessert Nutrition panel is without alcohol. If you add alcohol the net carb per serve is the same but the kcal per serving will be 244 kcal