Brown the ground beef in a large skillet over medium heat. Drain off any excess fat.
Add the chopped onion to the skillet and cook until soft, about 5 minutes.
Stir in the minced garlic, Italian seasoning, salt, and pepper. Cook for 1 minute until fragrant.
Pour in the beef broth and bring the mixture to a simmer.
Add the dry pasta to the skillet, stirring to submerge it in the liquid.
Cover the skillet and cook according to the pasta package directions, usually 10-12 minutes, stirring occasionally to prevent sticking. The liquid should be mostly absorbed.
Reduce the heat to low. Stir in the heavy cream.
Remove the skillet from the heat. Sprinkle the cheddar and mozzarella cheeses over the top. Cover the skillet for 3-5 minutes until the cheese is fully melted and gooey.
Garnish with fresh parsley before serving.
Notes
If the sauce seems too thick after adding the cream, add a splash more broth or milk until you reach your desired consistency.
You can substitute ground turkey or ground sausage for the ground beef.
Use freshly grated cheese for the best melting results.