Arrange the mushrooms and celery on a platter and scatter the parsley leaves around. Squeeze the lemon juice evenly over the platter then liberally drizzle the salad with extra-virgin olive oil, about 3 tablespoons. Season the salad with salt and lots of black pepper and toss with your finger tips to combine. Using a vegetable peeler, shave cheese and scatter a couple of handfuls Parmigiano-Reggiano over the salad.
Recipe courtesy of Rachael Ray