Editor's note: The recipe and introductory text below are reprinted from Andreas Viestad's book Kitchen of Light: New Scandinavian Cooking.

　　People tend to differ as to what the real, authentic food traditions are. These differences can cut across countries, regions, or even families (my wife and I can never agree on what to have for Christmas dinner). But on one subject, there is no disagreement among the people of Norway, Sweden, and Finland: Gravlaks should be served with a sweet mustard sauce.

Ingredients

　　6 tablespoons sweet grainy mustard, or to taste

　　2 to 3 tablespoons Dijon mustard

　　1 tablespoon sugar, or to taste

　　1 to 2 tablespoons vinegar

　　1 cup vegetable oil

　　2 to 3 tablespoons finely chopped fresh dill

　　Combine the sweet mustard and 2 tablespoons of the Dijon mustard in a medium bowl. Add the sugar and 1 tablespoon of the vinegar. Gradually add the oil, whisking constantly. Adjust the flavors as necessary. The sauce should be neither overly sweet nor overly acidic. Add a little water if the sauce gets too thick. Stir in the chopped dill. It will keep, refrigerated, for 2 to 3 weeks.