1Heat oven to 350°F. Spray 8-inch square pan with cooking spray. Cook and drain pasta as directed on package.
2In pan, mix pasta, chicken, frozen vegetables, soup and broth. Bake uncovered 35 to 40 minutes or until bubbly around edges.
3Top with tomatoes. Sprinkle with onions and cheese. Bake uncovered about 3 minutes or until cheese is melted.