The spelling varies, and along with it the origins, but…
Of central Asian origin, bok choy is a favourite in the cabbage family. A member of the brassica rapa tribe that is also related to the turnip, this cruciferous vegetable is found in several cuisines but is likely best known in Chinese cookery.
And like its crunchy cousins, it can be pungent given its chemical nature — a chemical nature designed to protect the plant — that is akin to the onion or garlic: when you cut up the plant, chemicals mix and mingle and produce a sulphuric-nitrogen defensive system (the mustard gas of World War I wasn’t just randomly so named). On a sulphur “pungency scale” out of 10, you could imagine Brussels sprouts at a nine and green cabbage at a seven, while bok choy is a mere three.
Bok choy is among the oldest species and is an essential ingredient in the Asian larder. It is simply delicious blanched and then sautéed with sesame oil, ginger and garlic.