To make the Okonomiyaki batter, combine flour, potato or corn flour, dash stock or salt, eggs and water in a large bowl. Let sit in the fridge for 30 minutes.
Combine the cabbage and pickled ginger and add to the batter. Mix well.
Brown the bacon in a lightly oiled pan. Arrange the sliced octopus around the bacon.
Spoon the batter mixture over the bacon and octopus and quickly spread out evenly. Cook on medium heat for about 6-7 minutes or until the base is browned.
Turn and cook, poking a few holes in the top of the pancake to allow steam to escape, for another 5 minutes or until the thick pancake is cooked through.
Serve hot with Otafuku sauce and drizzle lots of mayonnaise over the top. Sprinkle with spring onions and bonito flakes.