Cook the pasta according to package directions.
Meanwhile, in a large skillet, cook the beef and onion over medium heat until the beef is no longer pink. Drain the fat. Drain the pasta as well and then add it to the meat mixture.
Stir in the tomatoes, relish, mustard, ketchup, steak seasoning and seasoned salt. Bring the sauce to a boil and then reduce to a simmer and let the beef pasta cook uncovered for five minutes.
Sprinkle the top with cheese and remove the skillet from the heat. Cover and let the cheese melt. Garnish with green onions and serve.
