1) Add water to a slow cooker till it is about half full.
2) Add the beef and let it cook over medium heat till thw water has started to foam.
3) Skim and discard any fat that might have risen to the surface.
4) Add the salt, pepper and olive oil, cover the cooker and let the ingredients cook for 20 minutes.
5) Remove the cover, add the potatoes, carrots, wild celery and onions.
6) Cover the cooker once again and cook over high heat for 15-20 minutes.
7) Ladle the soup into a serving bowl and serve while still hot.