Green Beans with Toasted Hazelnuts Vinaigrette

2/3 cup hazelnuts (about 3 ounces), coarsely chopped
1 1/2 pounds green beans, ends trimmed
1/4 cup butter, room temperature
2 teaspoons unseasoned rice vinegar
Coarse salt or sea salt
Coarsely ground black pepper

Place hazelnuts in small nonstick skillet. Stir over medium heat until lightly toasted, about 8 minutes. Sprinkle with salt and set aside.

In a medium saucepan over medium-high heat, bring water to a boil. Add the beans and partially cook for 4 to 5 minutes (depending on the degree of doneness you want). Remove from heat. Drain the beans in a colander and immediately immerse them in an ice water bath to stop from cooking; drain and set aside.

Melt butter in same pot over medium-high heat. Add beans and vinegar; toss to coat and heat through, about 2 minutes. Season with salt and pepper. Transfer to serving platter. Sprinkle with hazelnuts and serve.

Makes 6 servings.