Hippocrates Soup

1 medium celery knob or root. If don't have, we can substitute it with 3 or 4 branches of celery. A small amount of parsley 2 medium Australian brown onions 2 small leeks. If don't have, substitute it with 2 additional medium onions several cloves of garlic 1 pound of potatoes (1 pound: 0.45 kg) Use low fire to make the soup. Time required is about 2 hours. Don't boil the soup. Lastly, don't eat the ingredients.