what is Takoyaki
Takoyaki (たこ焼き or 蛸焼) or “octopus balls” is a ball-shaped Japanese snack made of a wheat flour-based batter and cooked in a special molded pan. It is typically filled with minced or diced octopus (tako), tempura scraps (tenkasu), pickled ginger (beni shoga), and green onion (negi). The balls are brushed with takoyaki sauce (similar to Worcestershire sauce) and mayonnaise, and then sprinkled with green laver (aonori) and shavings of dried bonito (katsuobushi).
Takoyaki was first popularized in Osaka, where a street vendor named Tomekichi Endo is credited with its invention in 1935. Takoyaki was inspired by akashiyaki, a small round dumpling from the city of Akashi in Hyōgo Prefecture made of an egg-rich batter and octopus.
Takoyaki was initially popular in the Kansai region, and later spread to the Kantō region and other areas of Japan. Takoyaki is associated with yatai street food stalls, and there are many well-established takoyaki specialty restaurants, particularly in the Kansai region. Takoyaki is now sold at commercial outlets, such as supermarkets and 24-hour convenience stores.
The oldest known takoyaki store is Aizuya in Osaka. Founded by Tomakichi Endo, it has been open since the 1930s. The first takoyaki included beef and konjac, but later Endo switched to using the now traditional octopus and added flavor to the batter. The takoyaki are then eaten with brown sauce, similar to Worcestershire sauce. The food, known as “octopus balls”, quickly became popular throughout Japan
cited from wikipedia