Preheat an outdoor grill for medium high to high heat and lightly oil grate.
Take two pieces of aluminum foil about 12 to 15 inches each and lay them down in a cross pattern, one over the other. Place the chicken breast, onion, potato, green bell pepper and barbecue sauce in the center of the foil. Bring up all eight corners of the foil and twist the top together to resemble a "kiss".
Grill each package over medium high heat for 30 minutes, or until internal chicken temperature reaches 180 degrees F (80 degrees C).