DIRECTIONS
Place the tuna on a plate and salt generously on all sides.
Let it sit at room temperature for 30 minutes.
Transfer the tuna to a heavy pot just large enough to accommodate it in one layer and cover with oil.
Set the pot over low heat and cook for 30 minutes. You want the oil hot but not bubbling.
Remove the tuna from the heat and let it cool completely in the oil.
Transfer the tuna and oil to a large jar, making sure the tuna remains covered in oil.
Store in the refrigerator. It will keep for weeks.