- Heat the oil in a large pot over medium heat. Add the chicken breast and sauté until browned on both sides, about 5-7 minutes per side. 
- In the same pot, add the water, ginger, scallions, onion, and garlic. Bring to a simmer over medium heat. Reduce the heat to low, cover, and let simmer for 90 minutes. 
- After 90 minutes, remove the chicken breast from the pot and set aside to cool slightly. Strain the broth through a fine mesh sieve or cheesecloth to remove the ginger, scallion, onion, and garlic. Return the strained broth to the pot. 
- Season the broth with the flavor packets from the ramen noodles and soy sauce. Stir well to combine. 
- Shred the chicken breast using two forks or your fingers and add them back to the pot. 
- Add the mushrooms and bok choy  to the pot and bring the broth back to a simmer. Let it cook for another 10 minutes. 
- Once the mushrooms are tender, add the ramen noodles to the pot and cook for 2 more minutes. Stir well to combine. 
- Taste the soup and adjust the seasoning with salt and pepper if necessary. 
- Serve the Asian Chicken Soup hot, garnished with additional chopped scallions if desired.