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 to the skillet, 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.