Wash and peel carrots. Remove from leek green leaves and roots. Cut carrots into fine stripes and leek into rings.
Bring beef stock and wine to the boil. Spice chicken with salt and pepper and fry them in butter all around. Now place chicken filets into soup and let them simmer about 15 minutes. Remove filets, add vegetable and let them simmer until tender. Remove with a sieve scoop. Boil down soup to half. Mix well 1 tbsp. flour and sour cream. Fold into soup and mix well. Season to taste with salt, pepper and 1 tsp. mustard.
Warm up filets and vegetable in sauce.
Serve with finley cutted chives and grated horseradish.