Best thing about the European Christmas markets is the street food.
This is "Tartiflette", a French dish from the Haute Savoie region of France. It is made with just a few ingredients - potatoes, reblochon cheese, lardons and onions, and you can have a serving or more at the Bruges Christmas market.
You cannot pass by it without getting some. In this cold weather it's just what the doctor ordered. Six euro will get you a portion big enough to share with another person.