Green Bean and Tomato Salad with Green Apple and Cider Dressing

Name: Green Bean and Tomato Salad with Green Apple and Cider Dressing
Ingredients: 2 tablespoons cider vinegar; 1 small shallot, coarsely chopped; 1/2 teaspoon Dijon mustard; 1/2 teaspoon kosher salt; 1/4 cup plus 2 tablespoons extra-virgin olive oil; 1 1/2 tablespoons boiling water; 1 pound green beans, trimmed; 2 pints grape tomatoes, halved; 1 large Granny Smith apple—peeled, cored and cut into 1/4-inch matchsticks; 1/2 small red onion, thinly sliced; 2 tablespoons chopped flat-leaf parsley; 2 tablespoons minced chives