Make the dough: In a large bowl, combine plain flour and salt. Gradually add lukewarm water, mixing until a dough forms.
Knead the dough on a floured surface for about 5-10 minutes until smooth. Cover with a damp cloth and let it rest for at least 30 minutes.
Prepare the filling: In a separate bowl, mix chopped spring onions, shiitake mushrooms (if using), 50g plain flour, Chinese five spice, and salt. Set aside.
Roll out the dough: Divide the rested dough into four pieces. Roll each piece into a thin circle (about 10-12 inches in diameter).
Add the filling: Brush a generous layer of vegetable oil onto the rolled-out dough. Sprinkle the filling evenly over the surface, leaving a small border around the edges.
Roll and shape: Roll the dough tightly into a log. Coil the log into a spiral shape, tucking the end underneath. Flatten gently and roll out again into a thicker pancake (about ½ inch thick).
Cook the pancakes: Heat a non-stick skillet over medium heat and add enough vegetable oil to cover the bottom. Once hot, add the pancake and cook for about 3-4 minutes on each side, or until golden brown and crispy. Add more oil as needed.
Make the dipping sauce: In a small bowl, mix soy sauce, sesame oil, and rice vinegar. Stir well.
Serve: Cut the pancakes into wedges and serve hot with the dipping sauce. Enjoy the flaky, crispy goodness!
