Chop onion and chives. Dice bread. Steam onions and caraway seeds in half the butter until translucent, lightly color. Fill up with beef broth. Add chives (reserve a small bit for garnish), make 5 min and season. Shortly before serving, toast the bread in the remaining butter until golden brown, add to the soup and sprinkle with chives.
Tip: As an alternative to the fresh chives, you can also use the freeze-dried.