For the buttermilk soup prepare a roux with butter and flour. This is poured with water, salt, pepper to it and once boil.
Stir in the buttermilk and simmer for about 10 minutes. Season with herbs and remove from heat.
Add sour cream (stir with flour if the soup is too thin), season to taste, ready.
Cut brown bread into cubes and fry in a pan with a little oil or butter until crispy and sprinkle into the soup.