Individual Campfire Sliced Potatoes

Not a formal recipe but good:
A large piece aluminum foil, spray Pam cooking spray in the middle, slice up a potatoe (like you would for fried potatoes), cut up a small amount of onion in small pieces, and put them in the middles of the aluminum fioil, shave off (with a knife) small pieces of margarine.butter and place on top of the potatoes/onions, add salt and pepper to taste, fold the aluminum foil around the potatoes so that it is completely sealed up. Wrap another piece of aluminum foil around the potatoes so it has two layers of aluminum foil (less likely to burn and if you puncture it hopefully it will only be the top layer) Place next to hot coals in the fire (don't set it in the fire or on the coals because the potatoes will burn). Cook for about an 1 1/2 hours.