Cut the leek into a semicircle, and the pepper into strips.
Cut the skinless fillet into large cubes (about 1.5 x 1.5 cm) and set aside.
Heat the vegetable oil and fry the pepper until tender.
Add the spray and put it out for just a couple of minutes. If using onions, fry the peppers and onions together until the onion is golden brown.
Pour water into a saucepan and put the fish, the water should be about 1 cm.
Bring to a boil, add salt, fry.
On the tip of a spoon, chop the paprika (to give the soup a pinkish color) and white pepper. Bring to a boil and cook over low heat until tender. Pour in the cream, let it boil and immediately remove from the heat.