Peel the hardboiled eggs and separate the whites and yolks; chop the whites finely.
Prepare a dressing with half of the oil and all of the lemon juice; add to this the chopped egg whites and shallots as well salt and pepper.
Coarsely chop the oyster mushrooms, then sauté them in a bit of butter; add salt, pepper, chopped parsley and porcini powder to taste.
Place the mushrooms in a salad bowl and cover them with the dressing; let it marinate for 20 minutes.
In another bowl, place the salad leaves on the bottom; cover with the oyster mushrooms and dressing.
Before serving, finely chop the egg yolks and sprinkle them over the mushrooms.
Source : Benoît Le Bigot