The day before, desalt the cod by soaking in water, changing the water approximately every 5 hours. Boil the cod for 10 minutes in a litre of milk mixed with a litre of water. Drain the cod and then flake with a fork, removing the skin and bones.
Boil the potatoes and mash with the milk. Add the eggs one by one, blending each one in well.
Chop and sauté the onions in olive oil, before adding to the mixture with finely chopped parsley. Sprinkle in the baking powder and flour and stir well. Leave to rest for 3 to 4 hours, if possible, to allow the batter to rise a little.
To finish, heat oil in a deep fryer. Form the batter into small ovals using two spoons and drop into the oil. Make sure the oil is not too hot as the fritters will burn without cooking through.
1 kg salt cod (or half this amount if already flaked)