Boil chicken in a pot of water with ginger for 30 minutes
Remove softened chicken and shred into small pieces
Strain broth in pot into the soup pot. Discard the residue except the ginger pieces. Add the ginger into the soup pot. Bring to boil.
Add carrots, celery, mushrooms, garlic, onion. Simmer for 15-20 minutes.
Add shredded chicken into the soup
Add ketchup, light soy sauce, dark soy sauce, pepper, sesame oil, salt, lemon juice. Simmer for 15 minutes and check for taste.
Drip beaten eggs slowly into soup stirring continuously.
Add cornstarch slurry and mix well. Simmer for 15 minutes before turning heat off.