When you want to prepare these fish to eat, you put it for two days in strong lye and one day in clean, pure water to make it as soft as you want it. After boiling it with an addition of salty butter, you can put it upon the very tables of princes as a well-liked and delicious dish."
Lutfisk on the Christmas Eve table is a remnant from the Catholic days, when all meat was strictly forbidden during fasting. Fish and porridge were the substitution foods, and since (more or less) only dry fish was accessible at Christmastime, this fish came to be the Christmas fish.
There are split opinions concerning the accompaniments to the lutfisk. Butter has already been commented by Olaus Magnus. Samuel �dmann (born in 1750) writes about Christmas Eve in his grandfather's home, when "the meal was started by strongly PEPPERED lutfisk." Mustard and mustard sauce was used with fish already by the Romans. In this country, mustard seems to be just as medieval as the lutfisk itself.
Many want their lutfisk with white sauce, salt, and pepper. Cajsa Warg writes in her cookbook, For Young Women, published in 1755, about a thick buttery sauce, thickened with flour, which was to be served with the lutfisk. And Dr. Hagdahl has a recipe for green pea pur�e, which you can serve with lutfisk or meat.
The pea pur�e, which is today substituted with canned or frozen small peas, doesn't seem to be a very common accompaniment with lutfisk. There's a recipe from the region of Dalarna, where you make the lutfisk with salted pork. On the West Coast some people pour hot pork fat over their fish, while others mix chopped eggs in the sauce. In Norway you can have stewed yellow peas and pork fat with your fish.
Thanks to the freezing facilities of today it would be possible to eat lutfisk all the year round, or at least prolong the lutfisk season. The Norwegians do. But in Sweden it seems like most people are reluctant to do this. It belongs to Christmas.
We eat thousands of tons of lutfisk each year. Half of this amount is dried, lyed ling, which has a lovely consistency and is fairly mild in taste. The other half is sathe, which has a coarser consistency and a more typical lutfisk taste.
-Author Unknown