To make the Guo Kui, brush some oil on a cleaned surface, preferably a smooth surface such as granite, marble or smooth wood.
Place a dough on top of the oiled surface. Brush rolling pin with oil, flatten the dough with palm and roll the dough into a thin oblong sheet.
Take one part of chickpeas and spread onto the sheet and press down so the chickpeas stick to the dough. Then, top it with chopped onions.
Take the top edge and fold over then press to the side to seal. This is to avoid the filling from falling out while rolling.
Continue to roll until you reach the other end of the dough. Try to pull the dough while rolling to get a thin layer.
You'll end up with a plump cyclinder with pointy ends. Turn it upside down so the cyclinder is standing. Let it rest for 10 minutes and continue with the rest of the ingredients.
After 10 minutes, take one cylinder and flatten it with minimal pressure into a disc. Go as far as you can without breaking the side (see notes). You'll have another chance to make it thinner later.
Wet one side with water and then dip it with raw sesame seeds. Set aside.