Preheat your air fryer to 400ºF (204ºC) for 5 minutes.
Cut the bacon in half and air fry it at 400ºF (204ºC) for 5 minutes. Set the bacon aside and save bacon oil in a small bowl.
After aif frying the bacon, chop them into smaller pieces.
Prepare the vegetables. Start by washing the Brussels sprouts, cabbage and green onion. Remove any outer leaves with discoloration then chop the cruciferous vegetables into smaller portions that would fit your food processor. You also need to slice a quarter cup of green onions.
Cut the Brussels sprouts and cabbage into thin slices. You can either do it with a knife, mandolin or a food processor. Then place the shaved vegetables in a large bowl.
To prepare the Okonomiyaki batter you need eggs, flour and water. First, beat the eggs in a small bowl. Then, mix the flour and water in a medium bowl. Then combine them to make a pancake batter.
Mix all the ingredients in a large bowl. First, add the green onion into the shredded Brussels sprouts and cabbage. Then add the bacon, drizzle the bacon oil (optional), season with salt and pepper. Lastly, add the prepared savory Japanese pancake batter. Mix until all the vegetables are evenly coated. Then divide it into 4 equal portions.
Air fry the shaved Brussels sprouts pancake mixture at 380ºF (193ºC) for 12-15 minutes. First, preheat the air fryer, then line the air fryer basket with parchment paper. Add the portioned savory Japanese pancake batter then shape it into a patty by using a spatula. Flip the pancake half-way. Continue air frying until golden brown.
Serve and enjoy your shaved Brussels sprouts! Top it with okonomiyaki sauce, kewpie mayo, green onions, and bonito flakes if desired.