Preheat a non-stick pan on low to medium heat. Add the oil to lightly coat the pan.
Pour some of the okonomiyaki mixture into the pan and make a 6-inch diameter pancake. Avoid pushing down on the pancake, it's supposed to be light and fluffy.
While the bottom cooks, without overlapping, lay down a few slices of bacon on top of the okonomiyaki.
Cook until the bottom of the pancake is lightly browned (about 3-5 minutes). Using a spatula, carefully flip the pancake such that the bacon-side is on the bottom.
Cook for an additional 3-5 minutes or until the pancake is lightly browned and the bacon is cooked through. If the okonomiyaki scatters during the flip, use a spatula to tuck the stray pieces back into the pancake.
Transfer the okonomiyaki to a plate and prepare the toppings.
Spread the okonomiyaki sauce on the pancake. Squeeze the mayonnaise on the pancake in long streaks. Sprinkle the aonori and katsuobushi and top with a few pieces of beni shoga
Cut the pancake as you like and serve immediately