1. Cook pasta according to package directions, omitting salt and fat. Drain.
2. While pasta cooks, heat a large skillet over medium-high heat. Add beef, onion, garlic, oregano, and salt; cook 5 minutes or until beef is browned, stirring to crumble. Stir in tomato paste; cook 1 minute, stirring frequently. Add tomatoes. Bring to a boil; cook 1 minute. Reduce heat to medium-low; cook 3 minutes or until thickened. Serve over pasta; top with cheese and parsley.