HEAT dressing in large nonstick skillet on medium-high heat. Add chicken; cook and stir 2 min.
STIR in rice, broth and broccoli. Bring to boil; cover. Reduce heat to low; simmer 5 min. or until chicken is cooked through and rice is tender. Let stand covered, 5 min. or until liquid is absorbed.
ADD tomatoes, cheese and onions; stir until blended.