Boil the potatoes. Chop the leek and cook in the broth for 8 minutes. Sprinkle fish with lemon juice and salt. Fry in hot oil for about 6 minutes. Mix herbs and mustard, spread on the fish after 4 minutes. Stir cream cheese into the leek stock, season to taste. Serve with fish and potatoes
(Plant substance: sulphide in leek)