In a wok or large sauté pan, add the oil, ginger, shallots, chilli flakes and shitake mushroom over medium heat and cook until it shimmer, stirring constantly until fragrant, about 2 minutes.
Increase the heat to medium-high. Add the bok choy and stir carefully to combine with the mushroom. Add the chicken stock, salt and pepper. Put the lid on and cook for another three minutes.
Remove the lid, stir in the thickener (if using) and continue cooking to evaporate some of the liquid and the stalks are soft to the touch. Approximately 3-4 minutes.
Drizzle the sesame oil and remove to a warm platter.
