Dough. Add butter grated on a coarse grater to the sifted flour. Grind the flour with butter, adding cold water (from the refrigerator), and sprinkle with salt. Knead the dough, wrap in cellophane and refrigerate for an hour or overnight.
Peel the potatoes and grate them on a coarse grater. Fry in a pan until tender, season with salt and pepper.
Cut the onion into half rings. Finely chop the mushrooms or cubes (and cut 7 pieces nicely for decoration). Fry the onions until golden brown, then add the mushrooms, stirring constantly for 5 minutes, then cover and put the heat on a medium level, and simmer for about 10-15 minutes.
In the meantime, take out the dough, roll it out and transfer to a mold with a diameter of 24 cm, lifting the sides. Pierce the bottom of the dough well with a fork and put in a preheated oven to 180 C for 15 minutes until golden brown.
Next, put a piece of cheese grated on a coarse grater on the bottom of the ruddy dough, then potatoes, again cheese, mushrooms and onions, and again cheese. Decorate with mushrooms and pour over eggs mixed with cream. Send to the oven for 20-25 minutes.