Prepare Rotini according to package directions; drain. In large skillet, heat oil. Add chicken, broccoli, carrot and onion; cook and stir over medium heat until broccoli is tender crisp. Add water, salt, bouillon and tarragon; cook and stir until chicken is cooked through. Add rotini and Parmesan cheese; toss to coat. Heat through. Serve immediately. Refrigerate leftovers.