Healthy Chicken Salad with Grapes, Apples and Tarragon-Yogurt Dressing

diced, cooked, skinless chicken breasts (see note)

halved red grapes (or quartered if the grapes are large)

diced apple (we prefer crisp, sweet apples in this recipe)

chopped pecans

chopped celery

nonfat plain Greek yogurt

cider vinegar

dried tarragon

sugar

kosher salt

smooth Dijon mustard

For serving: spinach or other leafy greens and whole grain wraps or toasted bread for sandwiches; greens as a base for a salad plate; or whole grain crackers or endive spears for serving as an appetizer