How to make
Boil the fish in salted water with the celery and carrots. Drain out the broth, save it. Chop the onion, mushrooms into slices and fry them in the oil.
Add the broth and black pepper. Boil for 10 minutes. Braise the flour until golden and add it to the rest.
Cook everything on low heat for 15 minutes. Remove it from the heat, add salt and butter. Tear the fish into pieces, pour the sauce over it and bake the dish for 15 minutes at 390°F (200 °C).
Serve immediately.
