The mushrooms are sliced very thin and tossed right away with lemon juice to keep them white. Celery and Parmigiano-Reggiano go in next, and white truffle is optional.

Ingredients
Equipment
Method
- Rinse mushrooms quickly under cold running water without soaking, then dry thoroughly. Slice lengthwise into very thin slices, about 1/8 inch (3 mm) thick.
- Put mushrooms in a shallow bowl or platter and toss immediately with lemon juice. Add celery and Parmesan flakes. If using the optional truffle, shave it very thin into the bowl with a truffle slicer or a vegetable peeler.
- Toss with olive oil, salt, and pepper, and serve promptly.