1 Preheat oven to 450 degrees F (230 degrees C) and cook whole (thawed) chicken for 10-15 minutes. 2  Then reduce the temperature to 350 degrees F (175 degrees C) and roast for 20 minutes per pound. Preheat oven to 450 degrees F (230 degrees C) and cook whole (thawed) chicken for 10-15 minutes. 2  Then reduce the temperature to 350 degrees F (175 degrees C) and roast for 20 minutes per pound.