Start by filling a large pot with water, add a generous amount of salt, and bring it to a rolling boil. Carefully add the large shell pasta to the boiling water and cook according to the package instructions until al dente. Once cooked, drain the pasta in a colander and set it aside.
In a large skillet, pour in the olive oil and warm it over medium heat. Once hot, add the finely chopped onion and minced garlic. Sauté the mixture for about 3-4 minutes, or until the onion becomes translucent and the garlic releases its fragrant aroma.
Increase the heat to medium-high and add the ground beef to the skillet. Using a spatula, break the beef into smaller pieces as it cooks. Continue cooking for approximately 5-7 minutes, or until the beef is well-browned and completely cooked through. Season the mixture with salt, pepper, and Italian seasoning, stirring to incorporate.
Pour the beef broth and heavy cream into the skillet. Stir the mixture thoroughly until fully combined. Let it simmer for about 5 minutes, allowing the flavors to blend and the sauce to slightly thicken.
Lower the heat to low and add the shredded cheddar cheese to the skillet. Stir continuously until the cheese is fully melted and the sauce is creamy. Next, fold in the chopped fresh spinach, giving it a moment to wilt in the warm sauce.
Carefully add the drained shell pasta to the skillet. Gently stir everything together, ensuring that the pasta is evenly coated in the creamy beef mixture. Allow it to cook for an additional 2-3 minutes to ensure everything is heated through.
Before serving, taste the creamy beef and shells pasta. Add more salt and pepper as needed to enhance the flavor according to your preference.
Notes
For a beautiful presentation, serve in a large bowl and garnish with parsley.