Oden is a Japanese winter dish consisting of several ingredients such as boiled eggs, daikon radish, konnyaku, and processed fish cakes stewed in a light, soy-flavoured dashi broth. Ingredients vary according to region and between each household. Karashi (Japanese mustard) is often used as a condiment.
Oden was originally what is now commonly called misodengaku or simply dengaku; konnyaku or tofu was boiled and one ate them with miso. Later, instead of using miso, ingredients were cooked in dashi and oden became popular.
Oden is often sold from food carts, and most Japanese convenience stores have simmering oden pots in winter. Many different kinds of oden are sold, with single-ingredient varieties as cheap as 100 yen.
In Nagoya, it may be called Kantō-ni and soy sauce is used as a dipping sauce.
In Kansai area they are sometimes called Kantō-daki and tend to be stronger flavoured than the lighter Kantō version.
Oden in Shizuoka use a dark coloured broth flavoured with beef stock and dark soy sauce, and all ingredients are skewered. Dried and ground fish (sardine, mackerel, or katsuobushi) and aonori powder (edible seaweed) are sprinkled on top before eating.
Udon restaurants in Kagawa Prefecture in Shikoku almost always offer oden as a side dish, to be eaten with sweet miso while waiting for the udon.
In Taiwan, the dish is called Heilun/Olun in the Taiwanese language. Besides the more traditional ingredients, olen also uses many local ingredients, such as pork meatballs and blood puddings. More recently, oden is offered in convenience stores and is known as guandongzhu in Mandarin.
In Korea, Odaeng is a street food that's sold from small carts and is served with a spicy soup. It's very common on the streets of Korea and there are many restaurants that have it on their menu or specialize in it.