Ingredients
1/2 cup plus 3 tablespoons extra-virgin olive oil
1/2 cup thinly sliced shallots, plus 1 tablespoon finely chopped (about 3 total)
1/2 cup dry white wine
3 pounds (about 100 small) mussels, scrubbed and debearded
1 teaspoon Dijon mustard
3 tablespoons rice-wine vinegar
Coarse salt and freshly ground pepper
3 tablespoons finely chopped fresh flat-leaf parsley, plus leaves for garnish
Lettuce leaves, for serving (optional)
Preparation
Heat 2 tablespoons oil in a large pot over medium heat. Add sliced shallots; cook, stirring, until translucent, about 3 minutes. Add wine; bring to a boil. Add mussels; cover and cook, stirring once, until mussels open, about 3 minutes. (Discard unopened shells.)
Remove mussels with a slotted spoon; discard cooking liquid. Chill mussels in a bowl in the refrigerator, about 1 hour.
Whisk together mustard, chopped shallots, and vinegar; season with salt and pepper. Pour in remaining 1/2 cup plus 1 tablespoon oil in a slow, steady stream, whisking until emulsified. Whisk in parsley. Vinaigrette can be stored in the refrigerator up to 3 days.
Toss chilled mussels with 1/2 cup vinaigrette. If desired, serve on the half shell on a bed of lettuce. Garnish with parsley. Drizzle with more vinaigrette, if desired.
