Bring a large pot of salted water to a boil. Add the medium shell pasta and cook according to the package instructions until al dente. Drain the pasta and set it aside.

In a large skillet, over medium heat, brown the ground beef. Use a wooden spoon to break it apart. Cook until it's no longer pink. Drain excess grease if necessary.

Add the diced onion to the skillet with the beef. Sauté until the onions soften, about 3 to 5 minutes. Then, add the minced garlic and cook for another minute, stirring frequently.

To the beef mixture, incorporate the Worcestershire sauce, hot sauce, smoked paprika, and dried oregano. Mix well. Next, pour in the tomato sauce. Stir to combine and heat through.

Add the cream cheese, beef stock, half-and-half cream, and tomato paste to the skillet. Stir continuously until the cream cheese is melted and fully combined. This step will result in a rich creamy sauce.

If you prefer a thicker sauce, sprinkle the all-purpose flour and stir until it thickens, which should take a minute. Adjust seasoning with salt, black pepper, and a pinch of red chili flakes if you're feeling adventurous.

Fold the cooked shell pasta into the beef sauce until well coated. Gently mix in the sharp cheddar cheese until melted. The cheese will add an extra layer of creaminess.

Transfer your creamy beef and shells to a serving dish. Top with freshly chopped parsley and a sprinkle of grated Parmesan cheese for a finishing touch. Enjoy while hot!