Directions

1. In a medium bowl add the flour, potato starch, baking powder, salt, chicken bouillon, garlic powder, and onion powder. Whisk well and set aside.
   
2. Wash green onions to remove any dirt. Pat them very dry with paper towel. Trim off the roots and split the onions down the middle so the thick white part is split into half. Chop them into 1 1/2-inch long pieces and transfer the green onions into the medium bowl with dry ingredients.
   
3. Mix well until the onions are coated in the flour mixture. Add ice water and then mix until the batter coats the onions. Do not over mix. In a small bowl mix soy sauce, rice vinegar, sesame oil, sesame seeds, and 3/4 teaspoon chopped green onions. Set aside.
   
4. Heat a large 12" cast iron pan over medium-high heat and pour in 2 1/2 tablespoons of vegetable oil. Once the oil is hot, swirl the oil around in the pan.
   
5. Add only the green onions into the pan with tongs. Evenly and thinly spread green onions across the pan. Then scrape out the remaining batter with a spatula and pour it over the green onions filling in any holes. You can use a spatula to spread the batter evenly so it fills in the gaps.
   
6. Reduce to medium heat and fry until the bottom is crispy golden brown and the onions are slightly charred with small bubbles forming all over the pancake, about 3 minutes.
   
7. Once you have a golden brown crust and the batter looks solidified, flip over with a large spatula. Pour remaining oil along the edges of the pan. Swirl the pancake in the oil to prevent it from sticking.
   
8. Fry until the other side is golden brown and the onions are a bit charred, about 2-3 minutes. Press the pancake down a few times with the spatula to make the pancake crispy.
   
9. Transfer the large pancake to a serving plate and cut into wedges with scissors. Serve immediately with dipping sauce.