1. Cook pasta according to package directions; drain.
2. Meanwhile, season chicken with garlic powder, salt and pepper, if desired.
3. Cook chicken, sweet pepper and onion in oil in large skillet over medium-high heat 5 minutes or until chicken is no longer pink. Add undrained tomatoes; simmer, uncovered, 5 minutes or until slightly thickened. Add olives, if desired.
4. Toss with hot pasta. Serve with shredded Parmesan cheese, if desired.