To speed up the prep time, use your kitchen scissors to cut the boneless chicken breast into large strips. Add them into a large soup pot, along with the water and smashed garlic cloves. Bring it to a boil over medium-high heat.
Then reduce heat, and cook at a gentle simmer for 5-7 minutes, or until chicken is cooked through. While the broth is simmering, use a slotted spoon to skim off the fat as much as possible.
When done, remove chicken from the pot and let cool on a plate (once cooled, shred the chicken into bite-sized strips).
In a separate pot, cook the rice noodles according to the package instructions. Then drain and rinse noodles in cool water for 30 seconds. Place the cooked noodles in each serving bowl.
Add the galangal powder, green onions, and shredded chicken into the broth. Stir and bring it to a boil again. Lower to a steady simmer, then season with fish sauce, white pepper, and lime juice. Taste & adjust seasonings if needed.
To cook the baby bok choy or baby spinach, place the greens on a ladle (hold them in place using chopsticks) and dip it into the soup for a quick blanch until the greens are just wilted. Remove, and place the greens into each bowl of noodles.
Finally, transfer the chicken pieces from the soup into each bowl of noodles. Then ladle the hot soup over. Enjoy!