String Bean and Potato Salad

adapted from Lidia Bastianich Ingredients 2 MEDIUM-TO-LARGE IDAHO POTATOES 1 POUND FRESH STRING BEANS, TRIMMED 3 TABLESPOONS OLIVE OIL 3 TABLESPOONS WHITE WINE VINEGAR ¼ TEASPOON SALT FRESHLY GROUND PEPPER TO TASTE 1 SMALL RED ONION, THINLY SLICED Directions  Boil the...