1 pound green and/or yellow beans, trimmed and cut into equal lengths
1/2 cup walnuts
1/4 cup white wine vinegar
3/4 cup extra-virgin olive oil
1 clove garlic, minced
1/2 cup chopped mint
Kosher salt and black pepper, to taste
1 red onion, sliced into thin half moons
3/4 cup crumbled feta cheese

Fill a large saucepan with water, and bring water to a boil over high heat. Blanch beans in boiling water until bright green, 1 to 2 minutes, . Plunge beans into ice water to stop cooking. Dry beans.

Meanwhile, preheat oven to 350 degrees Fahrenheit. Spread walnut on a baking sheet in a single layer and toast, shaking occasionally, until golden and fragrant, about 10 minutes. Chop walnuts.

In a bowl, whisk together white wine vinegar, olive oil, garlic and mint. Season dressing with salt and pepper.

In a separate bowl, combine blanched beans and red onion. Toss with dressing and top with feta and toasted walnuts.

Serve at room temperature. It's even better on the second day.