Potatoes and carrots cut into the same cubes, onions and garlic finely chop.
Mushrooms cut into cubes slightly more.
In a saucepan with a thick bottom fry all ingredients in butter for about 2-5 minutes (stirring). Add salt to taste and a pinch of Provencal herbs. (if there are none, then add a few grains of dry rosemary, it gives a special touch of soup). Add a pinch of nutmeg.
Add 1 liter of boiling water, bring to a boil and simmer for about 10 minutes.
Fish cut into large.
Add to pan. After boiling, simmer for 10 minutes.
It needs more salt, if required.
Add greens (green onions, parsley). Turn off the heat and let stand for a while.