Cut a 18 inch square of heavy-duty foil into 4 squares. In the center of each square place 1 tablespoon of oil and 1 tablespoon of popcorn. Bring the four corners of the foil to the center and make a pouch. Seal the edges well, allowing room for the expansion of the popping popcorn during cooking. With a string, tie each pouch to a long-handled kitchen tool, or stick. Place each pouch directly on hot coals and shake constantly till the popcorn is popped. Season with melted butter and salt. This makes as many pouches as you desire. Yum! Enjoy!