Preheat the oven to 425 degrees or a grill over medium high heat. In a small bowl whisk together the butter, ranch seasoning, and salt and pepper to taste.
Coat 4 large squares of foil with cooking spray.
Place the potatoes in a bowl and drizzle with 4 tablespoons of the ranch butter over the top. Toss to coat evenly.
Place a chicken breast onto each of the foil squares and season with salt and pepper to taste. Divide the potatoes evenly among the 4 foil squares and arrange them around the chicken.
Drizzle the remaining 2 tablespoons of butter over the chicken breasts. Fold the edges of the foil over the chicken and potatoes to make a packet.
Bake for 45 minutes or grill for 30 minutes. Open the packets and sprinkle the cheese over the chicken and potatoes. Leave the packets open and return to the oven or grill for 2-3 minutes or until cheese melts. Sprinkle with bacon and parsley and serve.