- 1/2cup Champagne vinegar
- 1 1/2teaspoons salt
- 1teaspoon black pepper
- 1/2cup finely chopped shallots (4 small)
- 1cup extra-virgin olive oil
- 1/2pound whole fresh portabella mushrooms, stems discarded
- 1/2pound fresh shiitake mushrooms, stems discarded
- 1/2pound fresh cremini mushrooms, trimmed
- 1/2pound chanterelle mushrooms, trimmed
- 1/2pound baby arugula, or regular arugula torn into bite-size pieces
- 2/3cup Parmigiano Reggiano shavings
- Whisk together vinegar, salt, pepper, and shallots in a large bowl. Add oil in a slow stream, whisking constantly until combined. Reserve half of the vinaigrette in another large bowl and add the mushrooms to remaining vinaigrette. Toss to coat and marinate 5 minutes. Transfer mushrooms to another bowl with a slotted spoon, discarding marinade.
- Heat lightly oiled grill pan over moderately high heat until hot but not smoking, then grill mushrooms in 3 batches, turning frequently, until golden brown, about 5 minutes per batch. Transfer as grilled to a cutting board and cool to room temperature.
- Cut portabellas into ½-inch-wide wedges, then halve shiitake and cremini mushrooms and cut chanterelles (if large) lengthwise into ½-inch pieces.
- Transfer mushrooms to reserved vinaigrette, tossing to coat, then add arugula, cheese and salt and pepper to taste and toss again.
Make ahead: Mushrooms (marinated) 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 can be made 1 day ahead, stored covered and chilled.