Assemble: Spray each piece of aluminum foil liberally with cooking spray. Rub the chicken breasts with barbecue seasoning on all sides.
Divide the potatoes and onion wedges evenly between the pieces of foil. Season the potatoes with garlic salt and pepper. Drizzle with reserved bacon drippings.
Brush the chicken pieces with barbecue sauce then center each piece on the potatoes and onions. Bring edges of foil together and crimp.
Make in the Oven: Arrange foil packets on a sheet pan. Bake in a preheated 375°F oven for 40-45 minutes, depending on the thickness of the chicken breasts. Bake until juices run clear and the chicken reaches an internal temperature of 165°F and potatoes are fork tender. Open the foil, then sprinkle each with cheddar cheese and bacon. Broil until the cheese has melted. Let stand 5 minutes, then serve garnished with chives and a dollop of whipped cream, if desired.
Gas Grill Instructions: Preheat grill to medium-high. Place foil packets on grill without touching. Decrease temperature to medium. Cook for 40-45 minutes, depending on the thickness of the chicken breasts. Bake until juices run clear and the chicken reaches an internal temperature of 165°F and potatoes are fork tender. Open the foil, then sprinkle each with cheddar cheese and bacon. Continue to grill just until the cheese has melted. Remove from grill and let stand 5 minutes then serve garnished with fresh chives and sour cream, if desired.
Campfire Instructions: Double wrap with foil, assembling packs in the same manner. Place foil packets into hot coals and cook for 40-45 minutes (depending on heat of coals) OR until the juices run clear and the chicken reaches an internal temperature of 165°F and potatoes are fork tender. Open the foil, then sprinkle each with cheddar cheese and bacon. Leave in coals just until the cheese has melted. Remove from coals and let stand for 5 minutes then serve garnished with fresh chives and sour cream, if desired.