Prepare a medium-sized bowl and add the flour, cornstarch, sea salt, garlic powder, onion powder, and icy cold water. Whisk well. Transfer the pancake batter to a measuring jug for easier pouring.

Add approximately 3 tablespoons of cooking oil to a moderately heated frying pan, spreading it evenly around the pan. Increase the heat to high and preheat the pan until the bottom is well heated.

Wait until the oil is hot enough for cooking (about 1 minute). To check, drop a small amount of pancake batter into the pan—if it sizzles, the oil is ready. Reduce the heat to medium-high.

Pour just under half a cup of pancake batter into the pan and spread it evenly and thinly.

Place 6 green onion tops on the pancake batter, parallel to each other. Pour a little bit of the pancake batter over and between the green onions, filling the gaps. Reduce the heat to medium.

Place some calamari, prawns, and red chilies (optional) sparingly over the green onions.

Use a spoon to drizzle half of the beaten egg over the pancake. While cooking, gently move the pancake in a circular motion from time to time to prevent it from sticking to the pan.

Flip the pancake when the top is partially cooked (about 4 minutes). If needed, add more cooking oil around the edges of the pancake to help release it. Cook for another 3 to 4 minutes.

Turn off the heat and transfer the pancake onto a plate or cutting board.

Repeat steps 2 to 8 with the remaining ingredients until everything is used up.

Slice the pancake into bite-sized pieces. Serve it with Korean pancake sauce.