Salt herring played a major role in the destiny of Europe and was brought to US shores by Scandinavian immigrants. This poor man's food — turned rich man's delicacy — was an all-important part of the diet of the poor in European cities. Two of these fatty fish furnish roughly 600 calories and two and a half ounces of protein, which is just about all the protein a person needs in a day. Overnight soaking not included in preparation time and cooking time is approximate. From the Minnesota Scandinavian chapter of the United States Regional Cookbook, Culinary Arts Institute of Chicago, 1947.