Sildesalat is a traditional herring salad originating from Norway. Although there are many variations, the salad is usually made with a combination of herring fillets, hard-boiled eggs, sour cream, mustard, onions, gherkins, and Granny Smith apples.
The salted herring is soaked in a mixture of milk and water before it's chopped and mixed with chopped apples, onions, and gherkins. The chopped egg whites are added to the salad, along with mustard and sour cream. The salad is chilled overnight and it's then topped with chopped egg yolks and a dash of paprika before serving.