Meanwhile, in 3-quart saucepan, melt butter over medium heat. Add onion; cook 3 minutes, stirring occasionally. Stir in flour; cook and stir 30 seconds. Slowly stir in broth; heat to boiling. Cook 3 to 4 minutes, stirring frequently, until thickened. Remove from heat; stir in cheese. Gently stir in cooked pasta, chicken, artichoke hearts, tomatoes, olives and parsley. Spoon into baking dish.