Shred the cabbage.
Cut the green onion and bacon into bite-sized pieces.
In a bowl, mix flour, water, and egg to make a batter.
Add the shredded cabbage, green onion, and bacon to the batter and mix well.
Heat oil in a pan and pour the batter in a round shape.
Cook on medium-low heat until both sides are golden brown.
Drizzle okonomiyaki sauce and mayonnaise on top.
Finish by topping with bonito flakes and aonori.