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 crepe batter.
02 - Preheat the takoyaki pan over medium heat and lightly brush oil into each hemisphere compartment to prevent sticking.
03 - Pour batter into the pan, filling each mold completely to the rim. Immediately add one octopus piece to each hole, then evenly distribute red ginger, green onion, and tempura scraps across all compartments.
04 - Cook for 1-2 minutes until edges begin to set. Insert skewers or chopsticks into the edge of each compartment and turn the ball 90 degrees, allowing uncooked batter to spill out and form the spherical shape.
05 - Continue rotating each ball every minute until evenly golden and crisp on all sides, approximately 8-10 minutes total cooking time. The exterior should be crispy while the interior remains tender.
06 - Transfer finished takoyaki to a serving plate using tongs or chopsticks. Drizzle generously with takoyaki sauce and mayonnaise in a crisscross pattern, then finish with aonori and bonito flakes. Serve immediately while hot.