Tas,
Thanks for posting.This process of baking fish on a bed of salt, and then, covering it has been a tradition in Cartegena, Murcia, on the southeast coast of Spain on Mar Menor, and the Mediterranean Sea, since time memorial. So pleased to see that you have posted such an interesting and delectable dish. The key: bake in earthenware clay casserole and do not gut the fish, only scale it.
Kindest regards.
Margcata