Daikon is the japanese name for the big white radish. It is called "luo bo" (白萝卜 bai luo bo) in mandarin hanyu pinyin, and "lo bak" in Cantonese.
It is a tuber that looks like the carrot, except it is whitish in colour. In fact, the carrot is known as "hong luo bo" which means "red radish".
It contains glucose, cane sugar, fructose, dietary fibre, vitamin C, amino acids, and potassium.
Photo source: Chris 73 at wikimedia.org.
Traditional chinese medicine practitioners believe that the it can helps to clear phlegm, stabilizes the breath, and is cooling. Children suffering from colds with dry painful throats and rackling cough are encouraged to eat it raw. It also promotes the absorption of calcium.
It is also affectionately acknowledged as the little ginseng. A Chinese folk saying "Radish in the winter, ginger in the summer, and the doctor's out of business." alluded to its efficacy in dietary therapy
Different parts of the radish can taste different. The top part is supposed to be spicy, and the tip is heaty. Better to slice the radish vertically and not cross section.
Although it can be quite spicy, that hasn't stopped people from using it raw in salads. It just has to be "treated" first. It is most popularly grated and marinated with salt and left to stand for a while to reduce its "bite".
The Japanese likes to pickle the daikon. One of the most distinctive pickled products is the yellow pickled slices that are almost always served in Japanese bentos.
It can be cut into chunks and cooked in soups or stew. After sufficient simmering, it loses its spicy taste and takes on the flavour of the soup or stew it is cooked in. It is popular in stews featuring beef, lamb or mutton.
I personally like the white radish in stews where they are simmered to melt-in-the-mouth softness and full of the flavour of the main meat ingredient. It is also indispensable in the tempura dipping sauce. The grated radish imparts a certain depth to the thin sauce.
I almost forgot to mention this, perhaps because this dish has nothing to do with soup. The big white radish is the ingredient in a very popular street food in Singapore: the fried carrot cake. The radish is grated finely, mixed with rice flour and steamed into big cakes. These cakes are then diced into small cubes before being fried in a big wok with eggs with or without sweet black sauce.
Photo source: LaRuth at Flickr
How to prepare
Remove the skin with a peeler like you would with a carrot. However nearly 98% of the calcium in daikon can be found in the skin. Therefore consider not peeling.
It can be sliced, diced, shredded and grated. It is also a great subject for decorative food carving.
If using raw, wash thoroughly, cut, slice or shred and let it stand in salt.
