How to cook
In boiling salted water, put the fish, wrapped in a cheesecloth, and boil for about 20 minutes, taking the foam out as you do.
Take out the fish and add the onion, celery, carrots and stalks of parsley, keeping them tied together, so that you can take them out later.
Add the cleaned and sliced potatoes. Boil for 20 minutes and pull from the fire.
Add the cleaned of bones and cut to pieces fish and add egg yolks.
Serve the fish soup hot.