Dough:

• In a large bowl, add flour, milk powder, sugar, yeast, and salt. Stir around with a spatula and make a well in the center. Add milk and melted butter into the well. Stir with the spatula until a rough ball forms. The dough should look shaggy and rough. In the same bowl, knead until smooth and elastic, about 5 minutes.
• Cover with plastic wrap and set aside in a warm place until doubled in size, about 60-90 minutes.
• Remove dough from the bowl and onto a clean surface. Using a bench scraper or knife, cut dough into 4 equal pieces. Roll each piece into a ball and return to the bowl, covered with plastic wrap.
• Working with one dough ball at a time, roll into a 10-inch circle. Repeat until you have 4 circles. (The unrolled dough balls can remain covered in the bowl.)
• Prepare ingredients for filling: finely chop the green onions and divide into 3 equal portions on a plate. Spoon duck fat into a small bowl and set aside at room temperature, to soften.
• On an unrimmed baking sheet, assemble the layers: add a 10-inch circle, brush a thin layer of duck fat, sprinkle a generous amount of scallions, then sprinkle lightly with salt. Repeat until you have 3 layers of duck fat + scallions. Finally, top with the last 10-inch circle. There will be 4 layers of dough circles but you will only be filling 3 layers with the duck fat and scallions.
  
• Using a knife or bench scraper, cut 16 even wedges. Make sure to leave a small circle of dough in the center -- this will hold the wedges together! The cuts will look like the spokes of a bicycle, radiating outward. Taking two wedges at a time, twist away from each other twice. Pinch edges together. Repeat until all the wedges have been twisted together; there should be 8 points altogether.
  
• Cover with plastic wrap and rest for 20 minutes. Preheat oven to 350F/175C.
• Remove plastic wrap and brush with egg wash. Bake until puffed and golden, about 22-25 minutes. Enjoy!