Add the water, garlic, coriander root, lemongrass, and galangal to a large pot. Bring to a gentle boil over medium heat.
Add the fish sauce, light soy sauce, dark soy sauce, white pepper, and palm sugar. Stir until the sugar dissolves.
Arrange the chicken thighs in a single layer in the pot. The liquid should come slightly more than halfway up the chicken.
Bring back to a gentle boil, then cover and reduce the heat to low. Simmer for about 45 minutes, flipping the chicken halfway through.
Turn off the heat and let the chicken rest in the cooking liquid for a few minutes. Serve hot with jasmine rice and spoon some of the broth over the rice.
Notes
Use the nutrition card in this recipe as a guideline.