Thin ribbons of Parmigiano-Reggiano carry the mushrooms' meaty robustness through each bite of greens. It might look like a lot of mushrooms when you're putting the salad together, but it allows everyone to have a generous helping.
Cooks' notes:
· Mushrooms (marinated but without additional vinaigrette) can be grilled and cut 4 hours ahead and cooled, uncovered, then kept, loosely covered, at room temperature. Pour off any juices before adding to vinaigrette.
· Vinaigrette keeps, covered and chilled, 1 day.
·Cheese can be shaved 1 day ahead and chilled in a sealed plastic bag.