Herring, apple, shallot, white bread pulp, cut into cubes, add softened butter and mustard and grind in a blender until smooth. Remove to refrigerator.
Peel the beets, cut into cubes 0.7 x 0.7 cm and bake for 50 minutes in foil with butter at a temperature of 180 degrees. Cool down.
Separate the head from one whole herring and pull out the spine. Place the mincemeat inside and refrigerate for 30 minutes until completely solidified.
Cut black bread thinly, salt and bake for 7 minutes at a temperature of 180 degrees. Brush bread with butter and place on a plate. Put the baked beets on the bread. Lay the bread and butter again on top of the beets.
Stuffed herring, cut into 5 equal parts, put on bread. Garnish with onion, dill and white caviar.