Reseason and restore cast iron whether your skillet is brand new or has been used for years and the seasoning is gone.

Re-seasoning
1. Preheat oven to 200 degrees.
2. Place pan in the oven and warm for 15 minutes.
3. Remove pan from oven and increase temperature to 450 degrees.
4. Rub oil over all surfaces of the pan, including the handle, using paper towels or a clean rag. Buff the pan to 5. remove excess oil so it no longer looks shiny.
6. Place the pan upside down on a rack in the heated oven. Place a sheet of foil on
the rack beneath it to catch any drips.
7. Heat the pan in the oven for an hour and then let cool.
8. Rub the pan with oil as before and repeat the process up to four more
times to set your initial layer of seasoning. The pan should develop a
gray or amber colored surface that resembles non-stick coating.