In a large bowl, combine the flour, potato starch, and salt until combined. Add the kimchi, kimchi juice, water, and scallion. Use a pair of chopsticks or a fork to stir the mixture until well-combined.
Heat a nonstick or cast iron pan over medium high heat. Add 2 tablespoons vegetable oil and add the batter to the pan, spreading it in an even layer. Fry until browned on one side. Flip the pancake and continue to cook until browned on the other side.
Meanwhile, assemble the dipping sauce by combining the sauce ingredients in a small bowl. Serve alongside the pancake!