Answer: changua is a colombian soup made the following way:
a) half milk and half water
b) half onion
c) one egg
d) a herb (cilantro = coriander)
you fry the ognion in butter until it becomes yellow. The you pour the mixed milk with water on it and put some salt and the coriander (something similar to parsley), and after a few minutes you put the egg inside (Spanish: escalfado). When the egg is cooked, you can retire the soup from the low fire.
Indications: frequently eaten late at night to make disappear unwanted side effects of alcohol consumption (seems to diminish the charge of liver by alcohol)