Creamy Beef and Shells

Creamy Beef and Shells 8 ounces medium pasta shells 1 tablespoon olive oil 1 pound ground beef 1/2 medium sweet onion, diced 2 cloves garlic, minced 1 1/2 teaspoons Italian seasoning 2 tablespoons all-purpose flour 2 cups beef stock 1 (15-ounce) can tomato sauce 3/4 cup heavy cream Kosher salt and freshly ground black pepper, to taste 6 ounces shredded extra-sharp cheddar cheese, about 1 1/2 cups In a large pot of boiling salted water, cook pasta according to package instructions; drain well. Heat olive oil in a large skillet over medium-high heat. Add ground beef and cook until browned, about 3-5 minutes, making sure to crumble the beef as it cooks; drain excess fat. Set aside. Add onion, and cook, stirring frequently, until translucent, about 2-3 minutes. Stir in garlic and Italian seasoning until fragrant, about 1 minute. Whisk in flour until lightly browned, about 1 minute. Gradually whisk in beef stock and tomato sauce. Bring to a boil; reduce heat and simmer, stirring occasionally, until reduced and slightly thickened, about 6-8 minutes. Stir in pasta, beef, and heavy cream until heated through, about 1-2 minutes; season with salt and pepper, to taste. Stir in cheese until melted, about 2 minutes. Serve immediately.