Get the dipping sauce ready:

1. Put soy sauce, vinegar, gochu-garu, green onion, and sesame seeds in a small bowl.
2. Set it aside for now, we’ll mix it later when we serve it.

Prepare pancake ingredients:

1. Combine the chopped seafood, pinch of salt and a pinch of ground black pepper in a small bowl. Mix it well and set aside.
2. Combine flour, potato starch, ½ teaspoon salt, and ¾ cup stock (or water) in a large enough to accommodate the green onions. Mix with a whisk until smooth.

Make green onion pancake:

1. Heat 2 tablespoons of the vegetable oil in a large nonstick skillet over medium-high heat and swirl to coat evenly.
2. Add the green onions to the batter to coat them. Using tongs or your hand, place them side by side in the skillet, alternating white end to green end, so they form a neat rectangle.
3. Add the seafood to the leftover batter in the bowl. Using your hands or tongs, spread the battered seafood on top of the battered scallions, scraping out any excess batter remaining in the bowl.
4. Add the sliced red pepper and pour the beaten egg over top of the pancake in the skillet.
5. Quickly wash your hands!
6. Reduce the heat to medium and cook for about 6 minutes, until the bottom is light brown and crispy.
7. Turn the pancake over with a large spatula. Drizzle the remaining 2 tablespoons vegetable oil around the edges of the skillet. Lift one edge of the pancake with your spatula and tilt the skillet so that the oil flows underneath the pancake. Cook for another 3 minutes until nicely browned and crisp.
8. Turn the pancake over again. Turn up the heat to medium high heat and cook for 1 minute, until the bottom turns crunchy.
9. Transfer to a large plate, with the egg and seafood side up. Serve right away with the dipping sauce.