I like to use up leftover eggnog in creative ways. I decided to adapt a traditional flan recipe and use eggnog in place of the milk. It came out quite tasty with a nice texture and unique flavor. The eggnog I used had sugar in it so I cut the traditional recipe sugar in half. The sugar in the recipe can be adjusted according to how sweet you like it, but not more than 1 cup total. The prep time includes 1/2 hour needed for the eggnog to cool.