1. Bring a large pot of salted water to a boil. Cook the pasta shells until al dente. Drain and set aside.

2. In a large skillet over medium heat, add a bit of oil and sauté the chopped onion until soft. Add the garlic and cook for 30 seconds until fragrant.

3. Add the ground beef to the skillet and break it apart with a spoon. Cook until browned, then drain the excess fat.

4. Stir in the tomato paste and cook for 1-2 minutes. Pour in the beef broth and simmer for 3-4 minutes.

5. Reduce heat to low. Add heavy cream and cream cheese. Stir until the mixture becomes smooth and creamy.

6. Season with salt, pepper, and Italian seasoning. Stir to combine.

7. Add the cooked pasta shells into the skillet. Gently mix until well coated with the creamy beef sauce.

8. Sprinkle in the shredded cheddar cheese and stir until fully melted.

9. Serve hot, optionally garnished with chopped parsley.