Remove skin from chicken and place in a soup pot. Add stock, wine, ginger, and onions and bring to a simmer. Simmer for 20-25 minutes or until chicken is just cooked through, skimming off any scum and fat that rises to the surface. Do not boil or stock will become cloudy.
Remove stems from Shiitake and add to stock. Slice Shiitake caps thickly and quickly saute in drops of olive oil until lightly browned. Set aside.
Remove chicken from pot and cut meat into long slivers discarding bones.
Strain stock carefully and discard ginger, onions and Shiitake stems. Wash out pot and add the cabbage and cook for 2 minutes. Add chicken, spinach and sesame oil and cook for one minute more. Correct seasoning with salt and pepper and serve at once.