Preparation
Heat oil in large nonstick skillet on medium-high heat. Add mushrooms and onions; cook 5 minutes, stirring occasionally. Stir in tomatoes with their liquid, the dressing and tomato paste.
Add chicken; cover. Reduce heat to medium-low. Simmer 12 minutes or until chicken is cooked through.
Sprinkle with cheese and bacon; simmer, uncovered, 5 minutes or until cheese is melted.