First Step: COOK THE PASTA

1. Boil the Pasta: Start by bringing a large pot of salted water to a boil. Add the pasta shells and cook according to the package directions, typically about 10-12 minutes, until the pasta is al dente.
2. Drain and Set Aside: Once the pasta is done, drain it well and set it aside. Be sure to save a little bit of pasta water (about 1/4 cup) in case you need to thin out the sauce later.

Second Step: COOK THE GROUND BEEF

1. Heat the Olive Oil: In a large skillet, heat the olive oil over medium-high heat. Add the ground beef, breaking it up with a spoon as it cooks. Brown the beef until fully cooked through and no longer pink, about 7-8 minutes.
2. Sauté the Onion and Garlic: Add the chopped onion to the skillet with the beef. Cook for 3-4 minutes until the onion becomes soft and translucent. Add the minced garlic and cook for an additional 1-2 minutes, until fragrant.
3. Season the Beef: Sprinkle the beef with Italian seasoning, paprika, salt, and pepper. Stir to evenly distribute the seasonings and cook for another minute.

Third Step: MAKE THE CREAMY SAUCE

1. Add the Cream Cheese: Reduce the heat to medium-low and add the softened cream cheese to the skillet. Stir it into the beef mixture until it melts and combines with the other ingredients, creating a creamy base.
2. Incorporate the Sour Cream and Broth: Add the sour cream and beef broth to the skillet, stirring until smooth. The broth helps thin out the sauce and creates a velvety texture. Bring the mixture to a simmer, stirring occasionally.
3. Add the Worcestershire Sauce and Cheeses: Stir in the Worcestershire sauce, mozzarella cheese, and Parmesan cheese. Continue stirring until the cheeses melt into the sauce, creating a smooth, creamy consistency.
4. Adjust the Consistency: If the sauce is too thick, add a bit of the reserved pasta water to thin it out. Stir in a tablespoon at a time until the sauce reaches your desired consistency.

Fourth Step: COMBINE THE PASTA AND SAUCE

1. Add the Cooked Shells: Once the sauce is creamy and smooth, add the cooked pasta shells to the skillet. Stir gently to coat the pasta evenly with the sauce and beef mixture. Let it cook for an additional 2-3 minutes to ensure the shells are well coated and heated through.
2. Taste and Adjust Seasoning: Taste the dish and adjust the seasoning as needed, adding more salt, pepper, or Worcestershire sauce to suit your taste.

Fifth Step: GARNISH AND SERVE

1. Garnish: Transfer the creamy beef and shells to serving plates. Sprinkle with fresh parsley and additional Parmesan cheese if desired.
2. Serve: Serve immediately and enjoy the rich, comforting flavors of this creamy, beef-filled pasta dish.