Prebake the tart shells according to the package directions.
Bring the eggnog to just below a boil.
In a medium bowl, whisk together the egg yolks and sugar until frothy.
Slowly pour in the eggnog into the egg mixture while constantly whisking, until combined.
Transfer to a pitcher or measuring cup with a spout, for easy pouring, and fill all the tart shells to just below the top.
Bake at 325F for 20-25 mins until the custard is set.
Remove from the oven and cool, finish by sprinkling nutmeg on to for garnish!