Boil potatoes, cut into cubes, with cod liver oil, drained, minced, eggs peel, separate whites from yolks and chop, onion finely chop, cheese grate. Salad can put layers, and all the ingredients mix well (except the egg whites, they are needed for decoration) and mayonnaise. Decorate as desired, I place the salad in the form of Mickey mouse. For decoration, used black olives, carrots. Instead of olives you can use an analogue of caviar.