Wash, clean and halve the mushrooms. Wash, clean and slice the tomatoes. Cut cabanossi into slices. Peel and finely dice onions. Wash and chop the parsley, except for something to garnish.
Heat the oil in a frying pan. Sauté the mushrooms and onions in it. Add cabanossi and fry briefly. Fold in tomatoes. Season with salt and pepper. Mix crème fraîche and put it on the mushroom pan.
Sprinkle with parsley and garnish.