In a medium salad bowl, mix together the mushrooms and parsley.
In a small bowl, whisk together the oil and lemon juice until smooth. Season with salt and pepper, to taste.
Add the oil mixture to the salad bowl and toss until all the ingredients are coated. Using a vegetable peeler, shave the Parmesan on top and serve.
Recipe courtesy of Giada De Laurentiis, 2008