Bok choy

Bok choy (American English, Canadian English, and Australian English), pak choi (British English, South African English, and Caribbean English) or pok choi is a type of Chinese cabbage (Brassica rapa subsp. chinensis) cultivated as a leaf vegetable to be used as food. Varieties do not form heads and have green leaf blades with lighter bulbous bottoms instead, forming a cluster reminiscent of mustard greens. Its flavor is described as being between spinach and water chestnuts but slightly sweeter, with a mildly peppery undertone. The green leaves have a stronger flavor than the white bulb.
Chinensis varieties are popular in southern China, East Asia, and Southeast Asia. Being winter-hardy, they are increasingly grown in Northern Europe. Originally classified as Brassica chinensis by Carl Linnaeus, they are now considered a subspecies of Brassica rapa. They are a member of the family Brassicaceae.
Other than the term "Chinese cabbage", the most widely used name in North America for the chinensis variety is bok choy (Cantonese for "white vegetable") or siu bok choy (Cantonese, for "small white vegetable", as opposed to dai bok choy meaning "big white vegetable", referring to the larger Napa cabbage). It is also sometimes spelled as pak choi, bok choi, and pak choy. In the UK, South Africa, and the Caribbean the term pak choi is used. Less commonly, the names Chinese chard, Chinese mustard, celery mustard, and spoon cabbage are also used.
There are two main types of bok choy, collectively called 小白菜 xiǎo bái cài ("small white vegetable") in Mandarin. One is white bok choy (Chinese: 奶白菜; lit. 'milky white vegetable') with dark green blades and white stalks, which is primarily cultivated in South China, and in Cantonese it is simply called baak choi (Chinese: 白菜; lit. 'white vegetable'; the same characters pronounced bái cǎi by Mandarin speakers are preferably used for Napa cabbage). The other is green bok choy (Chinese: 青白菜; lit. 'green white vegetable'; Chinese: 青菜; lit. 'green vegetable'; Chinese: 上海青; lit. 'Shanghai green'; Chinese: 青梗菜; lit. 'green-stalk vegetable'; Chinese: 小唐菜; lit. 'small Chinese vegetable') with light green stalks, which is more common in East China; the young and tender plants of green bok choy is called baby bok choy (Chinese: 雞毛菜; lit. 'chicken-feather vegetable'), which is less crisp and therefore may become too soft if overcooked.
In Australia, the New South Wales Department of Primary Industries has redefined many transcribed names to refer to specific cultivars. They have introduced the word buk choy to refer white bok choy and redefined pak choy to refer to green bok choy.
Bok choy cooks in 2 to 3 minutes by steaming, stir-frying, or simmering in water (8 minutes if steamed whole). The leaves cook faster than the stem. It is often used in similar ways to other leafy vegetables such as spinach and cabbage. It can also be eaten raw. It is commonly used in salads.
Dried bok choy is saltier and sweeter. Pickled bok choy remains edible for months. Immature plants have the sweetest, tenderest stems and leaves.
The raw vegetable is 95% water, 2% carbohydrates, 1% protein and less than 1% fat. In a 100-gram (3+1⁄2-ounce) reference serving, raw bok choy provides 54 kilojoules (13 food calories) of food energy and is a rich source (20% or more of the Daily Value, DV) of vitamin A (30% DV), vitamin C (54% DV) and vitamin K (44% DV), while providing folate, vitamin B6 and calcium in moderate amounts (10–17% DV).
Bok choy evolved from the mustard plant in China, where it has been cultivated since the 5th century CE. It can be traced to the Yangtze River delta area, one of the world's oldest agricultural regions. It also has been traced to the Yellow River Valley where archaeologists found Chinese cabbage seeds dating back 6,000 years.
As bok choy grew in use, it spread to other parts of Asia and was eventually cultivated in countries such as Japan, Malaysia, Indonesia, and the Philippines. Bok choy plantations were present in Japan and Malaya by the early 19th century. In Malaya, bok choy was not commonly consumed by the poor.
The vegetable was introduced to Europe in the mid-18th century. A Swede named Osbeck brought bok choy seeds to Europe during the same time period Jesuit missionaries brought similar strains of the vegetable to German scientists working in Russia. Bok choy was introduced to North America in the 19th century, but did not gain in use for another century.