Peel, wash and slice the potatoes and carrots. Clean, wash and cut leek into rings. Fry the potato and carrot slices in 2 tablespoons of hot oil for about 10 minutes. Add the leek 5 minutes before the end of the cooking time and fry. Rinse fish cold and pat dry. Cut into cubes and sprinkle with lemon juice. Fry in the remaining oil all around for about 5 minutes until golden brown.
Season with salt and pepper. Pour broth and cream on the vegetables and bring to the boil. Stir in mustard and sauce thickener. Season to taste with salt and pepper. Wash the chives, dab dry and cut into small rolls. Add to the vegetables with the fish and heat up briefly with