Boil the eggs. Grate the cheese and boiled eggs separately from each other. Cut the champignons into slices. Chop the onion. Chop the parsley. Separate the meat into fibers.
Fry the mushrooms in a dry frying pan for 3-4 minutes. Pour in vegetable oil and add onions to the champignons. Add salt and pepper and fry for another 5 minutes, stirring occasionally.
Lay out all the ingredients in layers, spreading each layer with mayonnaise and tamping down a little. Place mushrooms in the first layer, then meat, eggs and cheese. Spread chopped parsley over the cheese.