Potato-Bean Salad with Herb Dressing

Ingredients

• 1 pound potatoes (about 2 medium), peeled and cubed -
• 1/2 pound fresh green beans, trimmed and cut into 2-inch pieces -
• Dressing: -
• 1/3 cup buttermilk -
• 2 tablespoons mayonnaise -
• 2 tablespoons sour cream -
• 1 tablespoon Creole mustard -
• 1 tablespoon minced chives -
• 1 tablespoon minced fresh parsley or 1 teaspoon dried parsley flakes -
• 1-1/2 teaspoons snipped fresh dill or 1/2 teaspoon dill weed -
• 1-1/2 teaspoons cider vinegar -
• 1 garlic clove, minced -
• 1/2 teaspoon salt -
• 1/8 teaspoon celery seed -
• 1/8 teaspoon pepper -