Mix all the ingredients in a large bowl. If there are lumps, give it a strain. Alternatively, you can mix all the ingredients in a blender too.
Heat the takoyaki pan over a medium high heat and brush oil over the entire surface. Pour the batter into the cavities.
Place one piece of octopus or whichever protein you are using, into each well.
Top with some spring onion.
When the bottom of the batter starts turning crispy, use 2 sticks or chopsticks to release the takoyaki from the cavity.
Add more batter as required.
Continue rotating the takoyaki occasionally as the batter becomes crispy and golden brown on all sides.
Once golden, place the takoyaki on a plate. Top with takoyaki sauce, kewpie mayonnaise, bonito flakes, seaweed and spring onion. Enjoy!