Thoroughly wash the watercress and pat dry.
Cut the roots off and roughly chop the watercress into 4 cm batch.
In a large pot heat oil and sweat onions and then add in the garlic and ginger, stir for one minute.
Add the watercress , stir , for a about two minutes and add water
Cook for about 15 minutes.
Taste and adjust seasoning, adding salt and/or pepper if desired.
Serve hot