When cooking chicken for 50 or more people, I like to start with one large chicken. For 70 people, figure on getting one 90-95 lb. chicken, which you can find at any freakish local grocer within 20 miles of a nuclear power plant. My rule of thumb is that the more cooling towers at the plant, the larger the chickens will be in the area.
Rub the chicken with giant blocks of water softener salt and ex-New York Giants linebacker Pepper Johnson. Place on a pallet, slide into the garage, and close it up. Douse the garage liberally with any flammable fluid- the cheaper the better. Remember to throw some fluid on the inside as well. That is what gives the chicken it's crispiness. Leave all solutions, car waxes, etc. in the garage during cooking. Some of the flavors in those old cans of cleaning fluid can impart quite a taste into the chicken, provided that you are not bothered by toxic fumes.
Call your neighbors and tell them to stay in their homes. After about 2 hours, the roof should blow off of the garage. The chicken is now ready. Call the fire department in order to douse any remaining flames. If the chicken isn't cooked all the way through, do not restart the fire- a propane torch works well for selective manual cooking.
Using a pitchfork and a neighbor to hold the pitchfork, slice the chicken in an up-and-down motion with a Stihl MS 880 chain saw and serve on cheap, flimsy paper plates.
Recipe serves 70 people or 1 Oprah.
This works best when the you have an unattached garage.