Green Bean and Fingerling Potato Salad

If fingerling potatoes are not available, small red potatoes, halved, may be substituted.

2 pounds purple and/or white fingerling potatoes, scrubbed 
1 pound green beans, trimmed
1/4 cup chopped mixed fresh herbs such as chives, garlic chives, thyme, parsley, mint and summer  savory leaves
2 tablespoons extra-virgin olive oil
1/2 teaspoon freshly grated lemon zest

 In a large kettle, simmer potatoes in salted water to cover until tender when pierced with a fork, about 10 minutes, and drain in a large colander. In a large saucepan, cook beans in 3 inches salted boiling water over high heat until crisp-tender, about 3 to 5 minutes. With tongs or a slotted spoon, transfer beans to colander with potatoes and drain well. In a large bowl, toss together warm potatoes, beans, herbs, oil, zest, and salt and pepper to taste. Salad may be made 1 day ahead and chilled, covered.