In 1-quart saucepan over medium heat cook potatoes, covered, in 2 inches boiling water until tender, about 15 minutes; drain.
Meanwhile, make vinaigrette: In bowl whisk together all vinaigrette ingredients. Place potatoes, mushrooms and beans in separate piles in large shallow dish; drizzle with 1/3 cup of the vinaigrette to coat. Cover; let stand 15 minutes. Heat broiler. Meanwhile, in bowl add chicken to the remaining vinaigrette; cover and let stand 15 minutes. Remove chicken from vinaigrette (discard vinaigrette); broil 4 to 5 inches from heat source about 8 minutes until juices run clear when chicken is pierced, turning once.
To serve, slice chicken breasts and arrange on 4 plates with potatoes, mushrooms and beans, dividing equally. Sprinkle with onion and garnish with cherry tomatoes.
Menu: Garlic Bread, Tangerines or Melon Wedges
Nutritional Information Per Serving: 540 calories; 31 g fat; 70 mg cholesterol; 410 mg sodium; 36 g carbohydrate; 5 g fiber; 31 g protein.
Source: The Potato Board