Heat oven to 450°F. Bake potato wedges as directed on package.
Meanwhile, in large saucepan, cook ground beef and onion over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is thoroughly cooked; drain. Stir in cheese, tomato sauce and chiles. Cook over low heat until cheese is melted and mixture is hot, stirring frequently.
Serve hot potato wedges with cheese dip.