Boil the eggs hard for about 10 minutes, rinse and peel them. Drain mustard gherkins, collect cucumber water. Mix mustard, yoghurt, sour cream, 4 tablespoons cucumber water and apple juice. Season to taste with salt, pepper and sugar
Peel onions and cut them into rings. Cut gherkins into slices. Wash and finely chop the dill. Wash, quarter, core and chop apples. Stir everything into the cream.
Cut herrings into strips, eggs into slices. Mix both carefully with the cream and let it stand in a cool place for 1-2 hours. Season again with salt, pepper and sugar. Garnish with dill flags and lemon slices