Place a clay pot on medium heat with the oil.
Saute the garlic without letting it color, then remove the pot from the heat and let it cool down slightly.
Next, add the kokotxas seasoned with salt, placing them with the black skin side down
Let the kokotxas rest, covered, over very low heat.
Occasionally give the pot a rotating movement for about 5-10 minutes.
Add the Txakoli.
Increase the heat, hold the pot with both hands, and rotate it with the characteristic motion so that the sauce thickens and heats up, until it begins to gently simmer and emulsify into a 'pil-pil'.
Add the chilli and finally the chopped parsley.
(Optional). Depending on how spicy you want the kokotxas, add the chili from the beginning, halfway through cooking, or at the end if you prefer them very mild.
To reduce the thickness resulting from the emulsification of the garlic, the gelatin from the kokotxas, and the oil, you can add a spoonful of fish stock or water.
It can also be done with a few drops of white wine or Txakolí.
Serve 8 pieces of cod per serving.