To prepare salad, bring broth to a boil in a medium saucepan; gradually stir in couscous. Remove from heat; cover and let stand 5 minutes. Fluff with a fork. Spoon couscous into a large bowl; cool slightly. Add chicken, onions, radishes, cucumber, parsley, and pine nuts; toss gently to combine.
To prepare dressing, combine vinegar and remaining ingredients, stirring with a whisk. Drizzle dressing over salad; toss to combine.
Note: You can toast nuts quickly in a dry skillet over medium-high heat. Stir frequently, and as soon as they become fragrant, remove the nuts from the pan.
MyRecipes is working with Let's Move!, the Partnership for a Healthier America, and USDA's MyPlate to give anyone looking for healthier options access to a trove of recipes that will help them create healthy, tasty plates. For more information about creating a healthy plate, visit www.choosemyplate.gov.