Clean and trim the mushrooms. Cut the stems flat, if necessary. Cut off about 1/4 of the mushroom lid horizontally. Dab meat dry. Heat the oil in a pan, fry the steaks on each side for approx. 3 minutes, remove and leave to rest for approx. 2 minutes.
Season with salt and pepper. Peel onions and cut them into fine rings.
Fry the mushroom heads and mushroom slices in hot frying fat for about 2 minutes, turning, and season with salt and pepper. Sort the salad, wash and shake dry. Cut meat into slices. Place the mushroom heads on a board with the slices facing upwards.
Spread the cottage cheese on top. Place salad, meat and onions on top and cover with the remaining mushroom slices. Stick them firmly with wooden skewers and sprinkle with pepper.