Marinate the chicken with half 1/4 tbsp of salt, 3/4 of the pepper, all the sesame oil, light soy sauce, and thick soy sauce. Rub until all the seasonings are distributed. Add the rest of the salt and pepper and repeat. Cover the chicken and leave aside for 30 minutes.
After 30 minutes, add cooking oil to the pan over medium heat. When the oil is hot, fry the onions and ginger for 2 minutes, or until softened and aromatic.
After the herbs are aromatic, add chicken. Stir to combine.
Remove potatoes from the water, shaking off the excess. Arrange them on top of the chicken.
Cover the pot. Reduce heat to medium-low, and set the timer for 1 hour. Stir evenly every 10 minutes or so.
After 30 minutes of braising, lightly stir the gravy. Add all the water and stir until combined. Cover the pan, stirring evenly every 10 minutes or so. Continue braising for the rest of the timer.
After 1 hour of braising, poke a fork through chicken and potatoes for softness. Continue braising for another 10 minutes if softer potatoes are preferred. Adjust gravy to taste.
Let it rest for 30 minutes before serving, or serve immediately.