For the accompanying sauce:
Rinse the kombu properly and then pat dry with a paper towel. Fill a saucepan with water and place the kombu to boil slowly, using low to medium heat, skimming the surface as it boils. Remove the pan from the heat right before it comes to a boil and discard the kombu to retain the stock.
While the stock cools down, in a mixing bowl, add the eggs, salt, and flour. Whisk together with the cooled stock to ensure the mixture is lump-free. Now, pour in the tofu, avocado, gari, spring onion, and cabbage and combine to a smooth consistency.
In a frying pan, pour a thin layer of frying oil and heat it up.
Add in about one-sixth of the batter and cover the pan to cook on medium heat for roughly 5 minutes. Turn the tofu okonomiyaki over and cook on the other side for the same amount of time. Remove from heat and set aside on a serving plate. Repeat this process with the rest of the mixture to make 6 or more “pancakes” in total. Use a small bowl to mix the ingredients for the accompanying sauce and drizzle the final mix all over.
Garnish each plate with some shredded nori and sesame seeds after spreading some mayonnaise on the tofu okonomiyaki as needed.