01 -
Bring a large pot of salted water to a boil and cook pasta shells according to package directions. Drain thoroughly.
02 -
Heat olive oil over medium-high heat in a large cast iron skillet. Add ground beef, crumble while cooking, and brown evenly for 3-5 minutes. Drain excess fat and set aside.
03 -
Add diced onion to the skillet and cook, stirring frequently, until translucent, about 2-3 minutes.
04 -
Stir in minced garlic and Italian seasoning; cook until fragrant, approximately 1 minute.
05 -
Whisk in all-purpose flour and cook until slightly browned, about 1 minute, to form a roux.
06 -
Gradually incorporate beef stock and tomato sauce, stirring continuously. Bring to a boil, then reduce heat and simmer, stirring occasionally, until sauce thickens, about 6-8 minutes.
07 -
Return cooked pasta and browned beef to the skillet. Stir in heavy cream and heat through for 1-2 minutes. Season with salt and pepper to taste.
08 -
Add shredded cheddar cheese and stir until fully melted and incorporated, roughly 2 minutes. Serve immediately.