1Heat oven to 375°F. Spray 2 1/2-quart casserole with cooking spray. Cook pasta as directed on package, adding broccoli for the last 2 minutes of cooking. Drain pasta and broccoli.
2Meanwhile, in casserole, mix chicken and bell peppers. In small bowl, mix soup, broth, mustard and onion; stir into chicken mixture. Stir in pasta and broccoli. Sprinkle with cheese.
3Cover; bake about 30 minutes or until hot in center and cheese is melted.