Prepare the ingredients: chop bok choy, dice onion, mince garlic, and slice carrots.
Heat sesame oil in a large pot over medium heat. Add onions and sauté until translucent, about 5 minutes.
Stir in garlic and ginger, cooking for an additional minute until fragrant.
Add sliced carrots and cook for another 5 minutes, stirring occasionally.
Add chicken thighs to the pot, followed by chicken broth and soy sauce.
Bring the soup to a boil, then reduce heat to low and simmer for 20 minutes.
Remove the chicken, shred it using two forks, and return it to the pot along with bok choy.
Simmer for an additional 5 minutes until bok choy is tender but still bright green.
Taste and adjust seasoning with salt and pepper as needed before serving.