At least 20 minutes, but ideally overnight, pat dry the chicken and coat liberally with salt.
Let chicken come to room temperature.
Place cast iron pan in the oven and preheat to 425 degrees.
Pat dry chicken again with paper towels. Cover the skin with the olive oil. Add either salt and pepper or a dry rub seasoning of your choice.
Take cast iron out of the oven (carefully!) and place chicken in the pan. Cook time will depend on the weight of your bird. See below section.
Let chicken rest for 10-15 minutes before slicing (don't skip this step! It ensures juicy-ness!!).
3 pounds = 40-45 minutes
4-4.5 pounds = 50-60 minutes
5 pounds = 65-75 minutes
If using a meat thermometer, place it in the thickest part of the thigh or breast until it reached 165 degrees F.