In a mixing bowl; rub stew meat well with salt.
Refrigerate 48 hours. In a saucepot over medium heat; brown meat in oil on all sides.
Add water, chicken broth, ginger, garlic and soy sauce.
Bring to a rapid boil for 5-10 minutes.
Reduce heat and simmer 1 ½ hours until meat is tender.
Taste for seasoning, add salt as needed.
Remove ginger and garlic.
Add one bunch of watercress stems; simmer 15 minutes until watercress stems are tender.
Add one bunch of watercress leaves; simmer 15 minutes.