Add the ground beef, onion, bell pepper and garlic powder to a large skillet over medium heat. Cook until ground beef is broken up and cooked through. Drain any fat and return skillet to stove top.
Stir in the flour until thick, about 1 to 2 minutes. Stir in the ketchup and Worcestershire sauce and scrape any browned bits off the bottom of the skillet.
Gradually stir in the beef broth, milk, salt and pepper. Bring mixture to a boil then add in dried pasta. Reduce heat to a simmer and cover, leaving the lid slightly ajar. Stir occasionally until noodles are tender, about 18 minutes.
Stir in the cheeses until incorporated into the sauce. Top with freshly chopped parsley. Serve warm and enjoy!