Cut the ends off the bok choy heads so that the leaves separate. Rinse leaves in a sink or basin full of water. Rinse a few times, using fresh water each time, as the grit tends to linger. Drain.
Heat extra virgin olive oil in a large pan or pot over medium heat. Saute garlic for a few seconds, then throw in the Shanghai bok choy leaves. If all of the leaves won't fit in the pan or pot, you can add the leftover leaves when it starts to cook down.
Add 1 cup of vegetable broth or water. Add the second cup if you think you need it.
Turn the heat to low and cover the pot to allow the bok choy to steam. Open the pot every couple of minutes to stir. Add sea salt, to taste.
Cook until the bok choy leaves are limp but still a vibrant green colour. Drizzle with sesame oil. Toss and serve.
If properly cooked, bok choy has a natural sweetness and is slightly crunchy towards the stems. Try this delicious and healthy dish with a bowl of brown or white rice and some traditional Korean miso soup.