A huge chunk of traditional Nordic food is either dirt-poor peasant food, or food that keeps for months on end so the brutal winter doesn't kill you regardless of whether you're a dirt-poor peasant or a hoity-toity lord (and this is what lutefisk is: usually low-quality dried fish cured in lye to soften it.)

Unfortunately this also means that many recipes are more or less lost, or really only written down in eg. family recipe books. And at least here in Finland we've also stopped using a majority of the local herbs we historically used, in large part because they're not seen as "fancy" (being herbs that dirt-poor peasants gathered from the woods) – not that we were ever that into spices, life being honestly pretty miserable for the majority of the population especially when serfdom was a thing. People had, well, other priorities