Cook pasta according to package directions; drain. Meanwhile, in a large skillet, cook beef and onion over medium heat until meat is no longer pink; drain., Stir in the pasta, tomatoes, beans, corn, salsa, green chiles, olives and taco seasoning. Bring to a boil. Reduce heat; simmer, uncovered, for 8-10 minutes or until heated through. Serve with sour cream and chips if desired.