Beat egg yolks by hand or with a mixer until they lightened slightly. If using a mixer, around 5 minutes of mixing should be sufficient.
Slowly add the sugar and mix until it's combined. The consistency should be similar to a thick batter.
Next, add nutmeg and vanilla and whisk until everything is combined.
Mix Bourbon and Amaretto and slowly add all to the batter. Use one tablespoon at a time to make sure everything blends well.
Once the mix is ready, pour it into a huge jar and let it sit in the fridge for a week.
After curing, whip the heavy cream and fold it into the batter. Do the same with half and half, and make sure everything is combined.
Taste-test your eggnog and optionally add some more Bourbon.
Then bottle it and store your eggnog in the fridge until you need it.
When serving, garnish with nutmeg, cinnamon stick, and star anise.