First step is to cure it with a dry rub. 1/2 cup of salt 1/4 cup of brown sugar, some pepper and a dash of powdered garlic and some dill. . Put down a good bed of your rub on some plastic cling film over aluminum foil and lay the filet skin down on the dry rub. Then layer some more of your dry rub over it.
next lay your second filet skin up over the first one and cover liberally with your dry rub. Wrap it all up in the cling film and aluminum. Set it in a dish to catch the drippings and put it in the fridge for 12 to 24 hrs with some weight over it to compress it. 2 liter juice carton worked well.
set a cast iron pan with mesquite wood chips on a single burner electric hot plate