Make the flax "egg" by mixing 1 tsp ground flax seed with 2 tbsp warm water and let it sit for a few minutes to thicken.
In a large bowl, whisk together the GF flour, tapioca flour, baking powder, salt and white pepper.
Add the flax "egg" and dashi and whisk until a smooth batter forms.
Slice the shiitake mushrooms and shred the cabbage and carrot.
Heat a large non-stick skillet over medium heat and add a drizzle of cooking oil.
Scoop about half the batter into the pan and spread it out into a round pancake shape.
Top the pancake with the shiitake mushrooms, cabbage and carrot.
Cook for 3-4 minutes until the bottom is golden brown, then carefully flip and cook the other side for another 3-4 minutes.
Repeat with the remaining batter and fillings to make 2 okonomiyaki pancakes.
Serve the okonomiyaki hot, drizzled with the homemade vegan Kewpie mayo and sprinkled with furikake seasoning.
