Hard-boiled eggs, cool, peel from the shell, cut in half, carefully remove the yolks.
With canned food, drain the oil, remove the bones, mash the fish with a fork.
Peel the boiled carrots and grate them on a fine grater.
Add the cheese and egg yolks, grated on a fine grater.
For dressing, mix sour cream, mustard and soy sauce.
Fish weight and season with a sauce. Mix everything well.
Using a pastry bag or spoon, fill the protein halves with the resulting mass.