Finish with a spicy glaze and a sprinkle of furikake, seasoning made of dried bonito flakes, sesame seeds, and seaweed.
Generously salt shredded cabbage and massage with hands for 20–30 seconds until it softens and releases some moisture.
Slice green onion into thin rings. Set aside green tops for serving.
Prepare the egg mixture: crack egg into a bowl and whisk with 2 tablespoons cold water until smooth (you can use fork at this step).
2. Mix the batter
In a large bowl, combine cabbage, okonomiyaki spices blend, half of green onion (that one with white parts), shrimp mince, and egg mixture.
Mix thoroughly until evenly incorporated.
3. Cook
Heat frying pan well and spread tablespoon vegetable oil across the surface.
Give cabbage mixture a final stir, lifting from the bottom to reincorporate any settled liquids.
Spoon mixture into frying pan, one portion per serving, shaping into a pancake about 1 cm thick. Level the surface. Cook over medium heat for 3 minutes, pressing gently with a spatula from time to time to ensure even cooking.
Flip and cook for another 3 minutes.
Flip again, carefully pour 50 ml water into frying pan, then cover with lid or foil for a couple of minutes to steam.
4. Finish
Increase heat to medium-high and cook for 1–2 minutes more, flipping as needed, until both sides are dry, lightly crisp, and golden.
5. Serve
Transfer pancake to a plate and spread okonomiyaki sauce.
Snip the corner of mayonnaise packet and drizzle in a thin zigzag over the top.
Finish with a sprinkle of furikake and green onion.