Put the second part of the herring on top, press it a little on top. Cover with a film from all sides. And in the refrigerator for at least three hours. You can leave it like that, and if there is a lid, close it. This snack can be prepared a day or two before the holiday. For the filling, you can take any products to taste. Cut everything into cubes, mix with the sauce. Lay out one half of the herring and cover the other, so it will be easier.