Mix the cream, egg yolk, mustard, herb salt and pepper into a marinade. Cover the opened fillets in the marinade and let them stand in a cool place for a day.
Preparation:
Remove the fillets from the marinade. Brush the inside with a little marinade and fold together. Wipe the marinade off the outside of the skin and pat dry.
Mix the marinade with creme fraiche and dill.
Roll the fish in the flour.
In a pan, fry the herrings in the heated clarified butter on both sides until they are crispy and brown. Keep the fillets warm.
Take the pan with the frying pan off the heat and stir in the marinade.
Serve the fillets with the sauce on preheated plates.
In addition: boiled potatoes or fried potatoes tossed in butter.