Rinse green onions under cold water and pat dry. Cut into 3 inch pieces. If scallions are thick, cut each piece in half lengthwise.
Combine flour, potato starch and baking soda in a medium mixing bowl. Whisk to combine.
In separate large mixing bowl, add water and soybean paste. Whisk until soybean paste is dissolved.
Gradually add the dry mix to wet mix, stirring the batter in between to ensure the ingredients are thoroughly combined and there are no lumps. Be careful not to overmix the batter.
Gently fold green onions into batter.
Heat a large cast iron skillet or non-stick pan over medium heat (you may need slightly higher heat if using a non-stick pan). When the pan is hot, add approximately 1 tbsp of canola oil.
Ladle approximately 1/3 batter into pan. Use a spatula to shape the batter into a circle and spread green onions throughout pancake.
Cook for 3-4 minutes or until bottom is golden brown. Flip and cook an additional 3-4 minutes. Remove from the pan and rest on wire rack. Repeat with remaining batter. Pancakes can be kept warm on wire rack in oven while you cook remaining pancakes.
Cut pancakes into 8 slices and serve warm with dipping sauce.