I can remember my mother making huge batches of these. She would often add sliced jalapeños, but I like them better without. This was not her exact recipe (because she never wrote it down and I was too much of a punk to write it down) but this is very good.
2 cups all-purpose flour (or a combination of all-purpose and rice flour)
2 cups very cold water
1 bunch scallions or spring onions, sliced in 2-3 inch slices
salt and pepper to taste
In a large bowl, mix flour, water and eggs until smooth. Add more flour or water as needed to get the consistency of a thin pancake batter. Stir in half of the chopped scallions, salt and pepper to taste. Let set for 10-15 minutes.
Check consistency before cooking-- the batter should be a little bit runnier than American pancake batter so that the pajeon cooks quickly and evenly.
Heat a skillet over medium flame and coat with a thin layer of oil. Pour about 3/4 cup pancake batter into the skillet, tilting the pan to cover the bottom.
(if you want to make it seafood style: add 3-4 shrimp thinly sliced and scallions or octopus thinly sliced after you have poured the batter into the pan)
Sprinkle over remaining scallions and cook for 6-8 minutes or until the bottom is brown and crispy.
A great dipping sauce recipe to go with this. . .
1/3 cup soy sauce
1/3 cup rice wine vinegar
1 TB sesame oil
1 TB minced garlic
1/2 tsp Korean dried red chili pepper flakes called "kochukara" (optional)