Season the chicken pieces with salt, pepper, and ground ginger, then lightly coat them with the cornstarch. Heat a large nonstick pan or pot over medium heat and add the oil. Once hot, sear the chicken pieces on all sides for about 5–7 minutes until golden and lightly crisp. Remove the chicken from the pan and set aside on a plate.

In the same pot, add the diced onion and sauté for 3–4 minutes until soft and fragrant. Pour in the chicken broth and use a wooden spoon to scrape up any browned bits from the bottom of the pan. Let the broth come to a simmer.

Return the seared chicken to the pot and let it simmer in the broth for about 8–10 minutes until fully cooked through. Add the oyster sauce, Thai chilies, and bok choy. Stir gently, then pour in the coconut milk and lime juice, and add the kaffir lime leaves if using. Stir everything gently to combine.

Turn off the heat as soon as the coconut milk is incorporated. Do not continue cooking for long after adding it, to prevent it from separating. Let the flavors meld for 2–3 minutes off the heat, then serve hot, optionally garnished with more lime zest or fresh herbs.

This dish pairs beautifully with steamed vegetables or a small portion of jasmine rice or cauliflower rice if you're counting points.