- 1 cup finely chopped sweet onion
- 1 tablespoon red-wine vinegar
- 1 tablespoon grainy Dijon mustard
- 2 1/2 pounds green beans, trimmed
- 2 tablespoons extra-virgin olive oil
- 1/3 cup finely chopped flat-leaf parsley
- Stir together onion, vinegar, mustard, 3/4 teaspoon salt, and 1/2 teaspoon pepper in a large bowl. Marinate about 10 minutes.
- Meanwhile, cook beans in a large pot of well-salted boiling water, uncovered, until just tender, about 6 minutes. Transfer to a large ice bath to stop cooking. Drain and pat dry.
- Whisk oil and parsley into onion mixture, then toss with beans.
- Artezin Mendocino Zinfandel '07 or Château de Chamirey Mercurey Rouge '07