Put the flour in a large mixing bowl. Gradually add the water to the flour and knead into a smooth dough. This process should take about 10 minutes. Cover with a damp cloth and let the dough rest for an hour.
While the dough is resting, prepare the filling. Start by adding the oil to a small pot over medium high heat. Heat the oil for about 7 minutes and allow it to cool. This "cooking" of the oil is supposed to bring out a nuttier flavor in the filling. This tip comes straight to you from Willy's mother, a Beijing local, and an authority on dumpling-making!
Once the oil is cooled, add the ground pork to a large bowl, along with the egg, chives, sesame oil, soy sauce, and cooked, cooled oil. At this point, you should make and boil a test dumpling and try it to make sure the taste is to your liking. You can then adjust by adding more salt if needed.
Once the filling tastes right to you, begin assembling the dumplings. The best way to do this is to divide the dough into manageable pieces and then rolling each piece into a rope. Cut them into small pieces (in a size similar to if you were cutting gnocchi, or about the size of the top part of your thumb).
Roll the pieces out into circles, and add about 1 1/2 teaspoons of filling to the center (it helps if you have an assembly line going, with one person cutting out the dough pieces, one person rolling it out, and one person filling/folding).
You can then make folds like you see in our other dumpling post, or you can just fold the circle in half and press them together. Willy's method is to fold the circle in half, press it together at the top, and then make two folds on either side. Whatever way works for you...they don't have to be pretty to taste good.
Place the dumplings about a centimeter apart on a parchment-lined baking sheet. When you're ready to cook, bring a large pot of water to a rolling boil. Carefully drop the dumplings into the water and keep them moving, so they don't stick to the bottom of the pot. Bring back to a slow boil, and cook until they float to the top and the filling is cooked through (about 5 minutes). Serve with our favorite easy-to-make dumpling sauce.