Prep the bok choy: remove the knobby bottom end of each and pull the individual segments (leaves) apart with your hands. Rinse the leaves thoroughly to rid them of any mud or grit.
Sauce: mix chilli oil or flakes, oyster sauce, and soy sauce together in a bowl and set aside.
Add the bok choy to a pan with ¼ cup of water. Cover and cook for 3-5 mins. Drain in a colander and set aside.
Heat the oil in the same pan and brown the shallots and garlic. Add the bok choy back into the pan and pour in the sauce. Turn the heat up and toss everything together for no more than a minute.
Take the pan off the heat and stir in toasted sesame oil and sesame seeds. Serve hot or at room temperature.