To make the pancakes: In large mixing bowl, combine flour, salt and sugar. Gradually pour boiling water into flour while stirring with chopsticks or a fork. Keep stirring until the dough starts to come together.

Once dough is cool enough to handle, knead on a floured surface for about 5–7 minutes, until it becomes smooth and elastic. Cover with a damp towel and let rest for 30 minutes.

While dough is resting, finely chop spring onions and mix in a small bowl with sesame oil and 2 tablespoons of vegetable oil. Set aside.

Divide rested dough into 4 equal portions. Roll one portion on a lightly floured surface into a thin, round circle, about 8–10 inches in diameter. Brush a thin layer of vegetable oil on top of the dough. Evenly sprinkle about ¼ of the spring onion mixture over the surface of the dough. Roll dough into a log or cylinder, and then coil it into a round shape, like a cinnamon roll. Flatten coiled dough gently with your hands, then roll it back out into a round pancake, about 6–8 inches in diameter. Repeat with each portion of dough.

Heat a small amount of vegetable oil in large skillet over medium heat. Once oil is hot, carefully place a pancake into the pan. Cook for 3–4 minutes on each side, or until golden brown and crispy. Repeat with the remaining pancakes.

To make dipping sauce: Combine all ingredients in a small bowl and whisk until sugar is dissolved.

To serve: Slice the pancakes into wedges and serve hot with dipping sauce.