01 - Whisk together flour, eggs, dashi stock, salt, soy sauce, and baking powder in a mixing bowl until completely smooth. The batter should have a thin, pourable consistency similar to heavy cream.
02 - Preheat the takoyaki pan over medium heat. Lightly brush oil into each half-sphere compartment to prevent sticking.
03 - Pour the batter into each compartment, filling them completely to the brim.
04 - Drop one piece of octopus into each hole, then evenly distribute the red ginger, green onion, and tempura scraps across all compartments.
05 - Cook for 1 to 2 minutes until the edges begin to set and turn golden brown.
06 - Insert skewers or chopsticks into the edge of each takoyaki and quickly turn 90 degrees. The uncooked batter will flow out to form the bottom of the ball. Repeat this turning motion every minute until all sides are evenly golden and crispy, about 8 to 10 minutes total.
07 - Transfer the takoyaki to a serving plate. Drizzle generously with takoyaki sauce and mayonnaise in a zigzag pattern. Finish by sprinkling with dried seaweed flakes and bonito flakes. Serve immediately while hot and crispy.