Combine the chopped seafood and season with a pinch of salt and ground black pepper in a bowl. Mix together and set aside.
In a deep bowl, combine flour, potato starch, salt, and water. Stir and mix until smooth. Add the scallions and coat in the batter.
Heat up a pan over medium heat and add 2 tbsp oil. When the oil is heated, add the scallions down in one layer to create a rectangular shape.
Scatter the seafood on top of the scallion. Place the sliced hot red pepper and pour any remaining batter on top.
Cook for about 3-4 minutes or until golden brown and crispy. Flip and add the remaining oil, making sure to swirl the pancake to distribute the oil and prevent it from sticking. Cook for another 2-3 minutes until crisp.