Scallion Pancake (蔥油餅)

This is something I learned to make from my parents when I was young.  My own kids in turn learned how to make this when they were little.  It's a great family activity! Note- Part 3 (pancake filling) is the key to make the pancakes crispy and layered. 

1. Place 4 cups of all purpose flour in a large mixing bowl. Stir in 1.5 cups of hot water (~200-deg-F, hissing but not boiling yet) gradually with a pair of chopsticks, then stir in 0.5 cup of room temperature water, and 0.4 cup of vegetable oil. Knead the dough in the mixing bowl till its surface is smooth. Wrap the dough in plastic and let it sit for 30 minutes.  Note- We used the KitchenAid Mixer with a dough hook at its lowest speed to knead the dough till it surface is smooth, for 6-7 minutes (stopped every couple of minutes to scrape the dough off of the hook, and started kneading again).  Note- This is exactly the same as the dough used in Beef Xian Bing.  The dough left from making Beef Xian Bing can be used to make Scallion Pancake.  Forgo the 0.4 cup of oil, when making a dough from scratch.
2. Place the dough on a flour-dusted kneading board, cut the dough in half. Work on one half of the dough first, by cutting it into 6 roughly even parts (doses). Each dose needs to be rolled into a round-shaped skin that is 6-8" in diameter (see leftmost picture below). Note- If we roll the rolling pin along the edge of the skin with one hand in an up-and-down motion, while turning the dose in counter-clockwise motion with the other hand handling the dose with the thumb on top and the other 4 fingers underneath, we can roll the dose into a round in 15-20 seconds. It takes some practice, but quite doable.
3. Pancake Filling: Place ~120g of finely chopped green onion in a small mixing bowl, add 3/4 tsp of salt, 1/2 tsp of white pepper, 1/2 tsp of five-spices, 1/2 cup of general purpose flour, stir and mix evenly. Now heat 1/2 cup of vegetable oil in a pan till hot (but below smoke point, remove pan when smoke shows!). Slowly pour the hot oil into the mixing bowl. Stir and mix evenly. Now we have the pancake filling. 
4. Spoon 1/12 of the pancake filling on the rolled skin and spread as evenly as possible (with finger, see middle picture below). Roll it up, while pressing both ends tightly and pulling both ends out as we roll (similar to the techniques used in Step 3 of the Sesame-Paste Biscuit, to create a longer roll).   Twist and spiral up the long roll as shown in the rightmost picture.  
   
5. Press the spiral from  top down with your hand, and continue to press with the fingertips of both hands, to flatten the spiral and to form a 6" pancake (~1/4" thick).  Note- Use a rolling pin instead of both hands could work as well, but a rolling pin could easily squeeze the oil out of the now puffy soon-to-be-a-pancake spiral. 
6. (Low-to-Medium Heat) In a 10-12" frying pan, heat 2 Tbsp of vegetable oil, Place two pancakes side-by-side in the pan (cover the lid).  Cook until the surface is golden, slightly brown (~3 minutes).  Flip and cook till the other side is golden-brown. The finished product is shown below. Note- Preserve the uncooked pancakes for longer period (weeks), by laying each one flat on baking pan over parchment paper and a layer of sprinkled flour powder, placing the pan in freezer until the pancakes are solidly frozen, and collecting them into freezer bags by separating each one with parchment paper.