A very easy recipe. I don't speak Spanish but this is what I got from the video.
Boil sliced potato in salted water. Add a mix of olive oil, garlic and fresh parsley (use electric mixer) to the boiling potatoes. Add "colorante" to the potatoes. The recipe didn't specify what kind. It is orange when dry. Is it this product? Colorante Alimentario from Ducros. Maybe some real saffron is a better option.
In the meantime cover some large pieces of cod in flower and fry in olive oil.
When the potatoes are done add the cod to the pot and simmer for 7 minutes. Place on plate and add some lemon juice and fresh parsley.