In 12-inch nonstick skillet, cook sausage over medium-high heat, stirring occasionally, 5 minutes or until sausage is cooked. Remove sausage and set aside.
In same skillet, cook red peppers and onion, stirring occasionally, 7 minutes or until vegetables are tender. Stir in sausage, Bertolli® Alfredo Sauce and cooked pasta shells; heat through.