Place salt cod in a dish with enough, water to cover.
Cover dish with, plastic wrap and refrigerate 8 hours, or overnight. If you have time, change water once or twice during soaking.
When fish is nearly done soaking, cut the potatoes into halves and place in a stockpot with enough water to cover by inch. Bring to a boil and cook 20 minutes, or until tender. Remove from heat and let cool.
Meanwhile, drain cod, rinse well, and place in a medium saucepan with enough water to cover. Bring to a boil, reduce heat, and simmer for 15 minutes, or until fish is tender. Remove from heat.
When fish is cool, carefully remove the bones and skin..
Mash potatoes with a fork or potato masher and place in a large mixing bowl. Add cod, onion, parsley, salt, and pepper. Beat egg yolks in a small bowl and add to codfish mixture. Stir to combine. If mixture is runny, add 1 to 2 tbsp. flour and mix well.
Like Christmas itself, these delicious holiday appetizers came to Brazil with the Portuguese, and these appetizers remain a local favorite.