Brown the ground beef and onion in a 12 inch enameled cast iron skillet over medium heat.
Add in the garlic and seasonings, then cook for another minute or two.
Add in the beef broth marinara, and heavy cream. Bring it up to a gentle boil.
Stir in the uncooked pasta, and simmer until the pasta is cooked through. Stir frequently.
When the pasta is done, stir in the parmesan cheese. (See note below)
Sprinkle on the melted cheese and bake in the oven for 5-10 minutes, or until the cheese is melted and bubbly. (Alternatively, you could then simply put a lid on the pan and leave it on the stove on very low heat until the cheese is melted, instead of using the oven.)
Allow the dish to rest 5 minutes before serving.
Enjoy!
Notes
If you want, you could also stir in a cup of ricotta cheese when you add the parmesan.