Add the olive oil, diced onion, garlic salt, pepper and red pepper flakes to a deep heavy bottomed pot or dutch oven. Cook over medium high heat for 2-3 minutes or until beginning to brown.
Add the beef to the pan. Continue to cook over medium-high until no pink remains. Add the worcestershire sauce.
Meanwhile, add 3 cups beef broth, tomatoes, tomato sauce, tomato paste, sugar and Italian seasoning to a stand blender. Puree until combined. Add to cooked beef. Bring to a boil, then lower the heat to medium. Simmer for 20 minutes.
Add the spaghetti to the pot mixing through the sauce. May break spaghetti, if desired. Cover and continue to cook for 15 minutes.
After 15 minutes, uncover and check the pasta for doneness, add reserved 1 cup stock. stir well. Continue to cook until pasta is al dente, adding additional broth if needed to loosen the sauce to your taste..
Just before serving, add 2 Tbsp chopped parsley to the pot, mix well. Serve immediately garnished with grated Parmesan cheese and additional parsley, if desired.