Peel the herring, remove the bones, and cut into small strips.
Cut the cucumber and onion into small cubes. Mix sour cream with cheese, add soy sauce, mustard, lemon juice, and oil. Stir.
Bread, I already had sliced, if not, then cut.
I covered the form with foil.
Put 2 slices of bread on the bottom and smear with sour cream sauce.
Then lay out the onion cubes.
Herring. Cucumber. Brush with sauce again.
So repeat three times.
The top layer should be bread.
Wrap the cake in foil and put it in the refrigerator for a couple of hours.
Then get it, cut into small squares, decorate as desired.