In a saucepan, whisk eggs, sugar and salt.
Gradually add 2 cups milk.
Cook over low heat, stirring constantly, until a thermometer reads 160º, about 25 minutes.
Pour into a bowl; stir in the vanilla, nutmeg and remaining milk.
Place bowl in an ice-water bath; stir frequently until mixture is cool.
If mixture separates, process in a blender.
Cover and chill for at least 3 hours.
When ready to serve, in a small bowl, beat cream on high speed until soft peaks form; whisk gently into cooled mixture.
Pour into a chilled punch bowl.
If desired, top with dollops of whipped cream and sprinkle with nutmeg.
