Step 1: Cook the Pasta

Bring a large pot of water to a boil and add a pinch of salt. Add the pasta shells and cook according to the package instructions (usually about 7-9 minutes). Drain the pasta and set it aside.

Step 2: Brown the Ground Beef

While the pasta cooks, heat the olive oil in a large skillet over medium-high heat. Add the ground beef and cook, breaking it apart as it browns (about 3-5 minutes). Drain any excess fat and set the beef aside.

Step 3: Sauté the Onion and Garlic

In the same skillet, add the diced onion and cook for about 2 minutes, until soft and translucent. Add the minced garlic and cook for another minute, until fragrant.

Step 4: Make the Roux

Add the flour to the skillet and stir constantly for about 1 minute to create a roux (this will help thicken the sauce). The flour should turn a light golden color.

Step 5: Add Liquids and Seasonings

Gradually whisk in the beef stock to the roux, stirring to prevent lumps. Once incorporated, add the marinara sauce and stir in the Italian seasoning, dried parsley, oregano, and smoked paprika. Stir well.

Step 6: Simmer the Sauce

Bring the sauce to a boil, then reduce the heat to low and simmer for about 6-8 minutes. Stir occasionally to allow the sauce to thicken and the flavors to meld.

Step 7: Combine Pasta and Beef

Add the cooked pasta shells and browned beef to the skillet, stirring well to coat everything in the sauce. Let it cook together for 1-2 minutes to let the pasta soak up some of the flavors.

Step 8: Add the Dairy

Stir in the heavy cream and cook for an additional 1-2 minutes, until the sauce is warm. Season with salt and pepper to taste. Then, add the sour cream and stir to combine, making the sauce rich and creamy.

Step 9: Add the Cheese

Fold in the freshly grated cheddar cheese, stirring constantly until the cheese is fully melted and the sauce is creamy.

Step 10: Serve and Enjoy

Serve the creamy beef and shells hot, garnished with extra cheese or fresh parsley if desired.