Cook first 3 ingredients in hot oil in a large skillet over medium heat, 5 minutes or until vegetables are tender. Add ground beef, and cook 8 to 10 minutes, stirring until beef crumbles and is no longer pink; drain and set aside.
Bring 1 1/2 cups chicken broth to a boil in a Dutch oven over medium-high heat; stir in shell macaroni, and return to a boil. Cook, covered, 8 to 10 minutes or until shells are tender, stirring occasionally.
Stir in beef mixture, cheese sauce from packet, basil, pepper, and remaining 1/2 cup chicken broth. Serve immediately.