Step 1

Cook the pasta according to the package directions. Meanwhile, in a skillet, cook the beef and onion over medium heat until the meat is no longer pink, then drain the liquid.

Step 2

Drain the pasta and place it in a 5-quart slow cooker. Stir in the beef mixture, cheese, pizza sauce, soup and pepperoni.

Step 3

Cover the slow cooker and cook the casserole on low for two to three hours or until heated through. If desired, top with basil or arugula before serving.