To make the batter, mix together the flour, dashi, salt, baking powder and sugar in a large bowl.
Add the chopped cabbage to the batter and mix well for at least 30 seconds, until fully combined. Add the eggs and mix, for about 15 seconds.
Preheat a non-stick pan at medium-low heat. Add 1 tablespoon of the sesame oil, making sure to coat the entire surface of the skillet.
Cook the okonomiyaki in batches. Spoon the cabbage and batter mixture into the skillet to form a pancake about 6 inches in diameter and about 1 inch thick. Don’t push down on the cabbage as you want to achieve a fluffy pancake. Gently lay bacon slices on top of the pancake. Do not overlap.
Cook the pancake for approximately 3 minutes. Use a long spatula to carefully flip the pancake, so the side with the pork belly is now facing down. Gently press down on the pancake with the spatula. The bacon will get crispy and cook into the pancake.
Cook for 5 more minutes, then flip the pancake again, so the side with the bacon is now facing up. Cook for about 2 more minutes. When it’s ready, the pancake should be browned on both sides. The bacon should be crispy and the cabbage inside will be soft and tender.
Transfer the pancake to a plate, pork side up, and add the toppings of your choice. Serve immediately.