Morel Vinaigrette:
2 ounces dried morel mushrooms
1/4 cup Champagne vinegar
1/2 small shallot, thinly sliced
2 teaspoons Dijon mustard
Salt and freshly ground black pepper
1/2 cup olive oil
3 tablespoons coarsely chopped fresh parsley leaves
Place morels in a bowl and cover with boiling water. Let sit until soft, about 30 minutes, then drain, reserving liquid, and coarsely chop.
Whisk together vinegar, shallot, mustard and salt and pepper in a medium bowl. Slowly whisk in the olive oil until emulsified. Use a little of the morel soaking liquid to thin, if needed. Fold in the mushrooms and parsley.