Preparation. Wash potatoes and cook in salted water for 20-30 minutes, depending on size. Rinse cold and peel. Leave to cool. In the meantime, peel onion for the salad and cut into fine slices.
Wash, quarter and core the apples. Cut apple quarters into thin slices and drizzle with lemon juice. Mix vinegar, salt, lemon pepper and sugar. Beat 2 tablespoons of oil into it. Season to taste.
Mix the marinade with the apples and onions. Cover and leave to stand for at least 1/2 hour. Season to taste again before serving. For the sauce, wash the dill and chop, except for 4 flags for garnishing.
Mix mayonnaise, dill, capers and milk. Season to taste with salt, pepper and horseradish. Cut the potatoes into slices. Heat remaining oil in a frying pan. Fry the potatoes until crispy while turning.
Season with salt, pepper and paprika. Arrange herring fillets rolled up with sauce, salad and fried potatoes. Garnish with dill flags.