Actually it is an ancient custom during Lent (La Cuaresma). When the Basque Fishermen returned from Newfoundland, Norway and The Fjords, the only way to preserve the cod fish was to salt it for their long journies home to The Basque Country. ( Vikings taught them to salt the Fish ) …
It is not as common amongst younger people to follow the Lent, however, the older generations do still abide.
Cod fish depending where it is from ( Wild Sable from Alaska), The Shetlands, Norway, Sweden and Finland: Basically, when fresh & wild it is lovely and can be
prepared in a million ways.
If you wish something Traditional for Lent, my grandmothers prepare Potaje de Espinicas. It is a chick pea stew with fresh spinach and strips of fresh or salt cod fish. We like it and prepare it all year long.
This same culture of the “baccalà” = the cod fish exists in Italy too. One can soak the fish in any type of milk you prefer and prepare it in a dish called: Mantecato alla Veneziana … Which means cod fish dip or butter.
One must remove the foam and discard all bones and the skin of the fresh cod.
Then simmer for 30 minutes in milk until tender.
Remove bones that were difficult to take out prior.
Take a mortar and combine garlic clove, parsley, black freshly ground pepper and thyme herb.
Combine with a Little Evoo.
Take this and add to the cod and with a stand up mixer, prepare the dip !!
Serve with Grissini bread sticks and flat breads.
And a bottle of Prosecco ! or Cava.