Rinse bok choy. Tear apart the large leaves and remove tough ends (*see footnote 2). Wash carefully and drain in a colander.
Chopped deep fried tofu and scallion, set aside.
Heat 1 tablespoon oil in a wok over medium high heat (highest heat on an electric stove) until hot. Add scallion and stir a few times until fragrant. Add bok choy, stir and cook for 1 to 2 minutes, until the bok choy is half cooked.
Add sugar and swirl in light soy sauce. Immediately stir a few times to mix well the sauce. Add deep fried tofu, stir to mix well, about 20 seconds.
Cover and lower to medium low heat (medium heat for electric stove). Cook for 30 seconds. Uncover and stir to check, 20 seconds. Cover and cook for another 10 to 20 seconds again, if necessary, until bok choy is cooked through and slightly caramelized on the edges. Stop heat and transfer everything to a plate.
Serve warm over rice.
Notes
Make sure to pick a larger head of bok choy to cook this dish.
If the bok choy is very large, cut the large and thick leaves in half lengthwise, so they are easier to stir fry and will cook evenly.