1) Into a saucepan, add in 1 bottle of wine along with sugar.
2) Add in grated nutmeg, next. Let the mixture come to boil.
3) In a bowl, add in the egg yolks and 2 glasses of wine. Whip well.
4) Pour in the egg yolks mixture into the saucepan, just as the wine mixture comes to a boil. Keep stirring continously.
5) As the mixture begins to thicken, pour it into mugs.
6) Serve the Mulled Wine warm.