Wash and clean the fish, boil it. Take it out and debone. Strain the broth.
Finely chop the carrots, onions and celery and put them in the broth.
To it, add the rice and chopped tomatoes. Add the oil and wine. Boil until the vegetables are cooked.
Prepare a thickening agent from the yoghurt, flour and eggs. Pour it into the soup that's been taken off the stove and season with the butter and vinegar. Serve sprinkled with parsley.