Matjes are a kind of pickled herring fillets - often made into this creamy salad - you can find them in the deli section in Germany and other European countries. I'm not sure how available they are in the US! This recipe is from my aunt Sabine, who's from Hamburg, and since I'm here visiting I had her make this for me.

This is a regional dish from northern part of Germany (and I think you can find it in other parts of N. Europe/Scandinavia). In German this is called "Matjesfilet Hausfrauenart" which literally means something like "housewife's style herring" indicating it's a kind of home-style, no frills dish. In general it's always made with apples and sour cream, and often dill. My aunt uses Herbes de Provence and allspice instead.