Malabar Spinach Soup (Canh Mồng Tơi)

Boil the prawn heads until flavoursome to make the broth. Add a teaspoon of sugar and fish sauce to taste.
Chop the spinach 1-2cm strips.
Add the spinach in when ready to eat. Like other types of spinach these cooks quite quickly as well.

http://outofthegarden.wordpress.com/2007/02/13/mong-toi-or-malabar-spinach-with-mushrooms/ 
(what the leaves look like)