Add onion, pepper, celery and chicken; cook until juices run clear when chicken is pierced with a fork.
While chicken is cooking, place sausage in a microwave-safe dish with just enough water to cover. Microwave on high 5 minutes; drain sausage and add to chicken mixture.
Add tomatoes to chicken mixture; cook 10 minutes over low heat.
Add tomato paste and soup; stir until well blended. Simmer 3 minutes or until bubbly.