Rawon: Indonesian's black soup

Don't be surprised by its colour. Rawon can give you a spicy taste that you will never dream of. This kind of soup has its own secret ingridient. It is called kluwek, a rocky poisonous black nut.  No need to be worry, my family and I used to eat this "deadly" casserole, and I am still alive to tell  you this culinary delight.
By nature, the nut is poisonous, thus, it has to be boiled to neutralize its poison.

Beware not to be tricked out by their hard shell , the look-like-stones beside are not stones for sure. Those are kluweks. Before use it, my mother usually uses a real stone to break its shell, and takes its black flesh.

Pictures are taken from:
http://radar-bogor.co.id/index.php?rbi=berita.detail&id=78406
http://manholic.blogspot.com/2010/05/rawon-kluwek-dan-batu.html