Green Beans with Sweet Onion Vinaigrette

By Tbird

Ingredients

• 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

Preparation

Step 1

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.