Boil the potatoes, carrot, eggs. Cool them. Peel the vegetables and eggs.
Grate finely the potatoes and carrot. Separate the yolks from whites, grate them too. Don’t combine the ingredients.
Dice the onion. The salad could feature either raw onion or soften – put it into boiled water for 10 minutes.
Pour off the oil from tinned fish. Discard the bones from the fish. Grind the mackerel with fork.
Set the salad following the succession of the layers: fish, a thin layer of mayonnaise, whites, a thin layer of mayonnaise, carrots, a thin layer of mayonnaise, onion, potatoes, a thin layer of mayonnaise, and the last layer is grated yolks. Put the salad in the fridge to get saturated.