In a medium stockpot or Dutch oven, cook beef over medium-high heat until browned and crumbly. Add onion and bell pepper; cook, stirring occasionally, until softened, 5 minutes.
Sprinkle with flour; cook, stirring frequently, for 2 minutes. Gradually add beef broth, stirring constantly, until well incorporated. Stir in tomato sauce, salt, and smoked paprika. Bring to a boil; add pasta. Reduce to a simmer. Cover and cook, stirring occasionally, until pasta is just tender, 15 to 18 minutes.
Stir in cream and cheese, stirring until cheese is melted. Garnish with parsley, if desired.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/beefy-mac-and-cheese/