The onions can be made 3 hours ahead. Let stand at room temperature.
Recipe information
Yield
Makes 4 to 6 servings
Ingredients
6 tablespoons olive oil
1 1/2 pounds red onions, thinly sliced
1 pound slender green beans, trimmed
1 1/2 tablespoons balsamic vinegar
3/4 teaspoon dried tarragon
Preparation
Step 1
Heat 3 tablespoons oil in heavy large skillet over medium-high heat. Add onions; sauté until deep brown, about 35 minutes. Season with salt and pepper. Cook beans in medium pot of boiling salted water until just crisp-tender, about 4 minutes. Drain; rinse under cold water until cool, then pat dry.
Step 2
Whisk remaining 3 tablespoons oil in vinegar and tarragon in large bowl to blend. Add beans and onions and toss to coat. Season with salt and pepper. Serve warm or at room temperature.
