The filling for these fish dumplings (yú jiǎo) is especially delicious thanks to the addition of fresh ginger and fragrant sesame oil. The bright green spinach dough offsets the pale white filling beautifully.
1-inchpiece fresh gingerpeeled and cut into fine slivers
2tablespoonsscalliongreen part only, finely sliced on the diagonal
2tablespoonslightregular soy sauce
To make the filling: cut the fish into 1-inch chunks, discarding any bones you discover along the way (bevel-tipped tweezers will help, if you have them). Put the fish in a food processor.
In a small bowl, combine the salt, pepper, chicken stock, soy sauce, wine, canola oil, and sesame oil. Mix well to create a seasoning liquid, and then pour about 2 tablespoons of the liquid into the food processor. Run the food processor, pouring the remaining seasoning liquid through the feed tube. Grind to a coarse paste, stopping occasionally to scrape down the sides.
Return the paste to the small bowl and mix in the ginger and Chinese chives. To develop the flavors, cover with plastic wrap and set aside at room temperature for 30 minutes. You should have about 2 cups of filling. (The filling can be prepared 1 day ahead and refrigerated. Return it to room temperature for dumpling assembly.)
To make the dough: place a large mixing bowl over a damp paper towel on your work surface, to keep in place while mixing. Add the flour and make a well.
Liquefy spinach and water together in a blender for about 90 seconds, or until there is an intensely green, smooth mixture. If needed, pause the blender to scrape down the sides.
Transfer to a small saucepan and heat over medium heat. When the spinach comes to a near boil (look for foam all around the rim), turn off the heat. Stir to blend in the foam and measure out ¾ cup. Use a wooden spoon to mix the flour while you add the ¾ cup spinach water in a steady stream. Mix together until you have a lot of lumpy bits, then knead the hot dough in the bowl until the dough comes together. Add spinach water by the teaspoon if the dough does not come together.
Continue kneading the dough on a lightly floured surface (only flour if necessary, and do so sparingly) for a couple more minutes until the dough is smooth and elastic. If your mixing bowl is very large you may finished kneading directly in the bowl. The dough should bounce back when pressed with your finger, but leave a light impression of your finger.
Place dough in a zip-top bag, seal tightly, pressing out excess air, and set aside at room temperature for 15 minutes up to 2 hours. The dough will steam up the bag and soften. After resting, the dough can be used right away, or refrigerated overnight and returned to room temperature before using.
To assemble the dumplings: Before assembling the dumplings, line a baking sheet with parchment paper. (If you plan to refrigerate the dumplings for several hours, or freeze them, lightly dust the paper with flour to avoid sticking.) Remove the dough from the bag, turning the bag inside out if the dough is sticky. Put the dough on a lightly floured surface and cut it in half. Put half back in the bag, squeezing out the air and sealing it closed to prevent drying.
Roll the dough into a 1-inch-thick log and cut into 16 pieces (cut in half, then cut each half in half, and so on to create pieces that are even in size. The tapered end pieces should be cut slightly larger). If your pieces are oval, stand them on one of the cut ends and gently squeeze with your fingers to make them round, like a scallop. Take each piece of dough and press each cut end in flour, lightly pressing the dough to about ¼ inch thick and set aside.
Next, flatten each dough disk into a thin circle, about ⅛ inch thick, either with a tortilla press (lined with plastic wrap), or with a heavy flat-bottomed object like a frying pan (also lined with plastic). Alternatively, use a dowel (which is a good lightweight rolling pin alternative for fast and flexible dumpling making) to lightly roll out each disc into an ⅛ inch thick circle.
To finish the wrappers, place wrappers one at a time on your work surface, and flour only if sticky. Use the rolling pin to apply pressure to the outer ½-to-¾-inch border of the wrapper leaving a slight "belly" in the center. Roll the rolling pin in short downward strokes with one hand while the other hand turns the wrapper in the opposite direction. Aim for wrappers that are about 3 ¼ inches in diameter. When a batch of wrappers is formed, fill them before making wrappers out of the other portion of dough.
For each dumpling, hold a wrapper in a slightly cupped hand. Scoop up about 1 tablespoon of filling with a bamboo dumpling spatula, dinner knife, or fork and position it slightly off-center toward the upper half of the wrapper, pressing and shaping it into a flat mound and keeping about ½ to ¾ inch of wrapper clear on all sides. Fold, pleat, and press to enclose the filling. This filling is rather soft and can easily squeeze out of the sides if you overfill your dumplings, so be careful.
Place the finished dumpling on the prepared baking sheet. Repeat with the other wrappers, spacing the finished dumplings a good ½ inch apart on the baking sheet. Keep the finished dumplings covered with a dry kitchen towel as you form wrappers from the remaining dough and fill them with the remaining filling.
To cook the dumplings: half-fill a large pot with water and bring to a boil over high heat. Add half the dumplings, gently dropping each one into the water. Nudge the dumplings apart with a wooden spoon to keep them from sticking together and/or to the bottom of the pot. Return the water to a simmer and then lower the heat to maintain the simmer and gently cook: a hard boil can make a dumpling burst.
Cook the dumplings for about 8 minutes, or until they float to the surface, look glossy, and are puffed up and a tad translucent. Use a slotted spoon or skimmer to scoop up the dumplings from the pot, a few at a time, pausing the spoon’s motion over the pot to allow excess water to drip back down before putting the dumplings on a serving plate. Cover the plate with a large inverted bowl to keep the dumplings warm. Return the water to a boil and cook the remaining dumplings. When done, return the first batch to the hot water to reheat for a minute or two. There is no need to reboil. If your pot is large enough, gently boil all the dumplings in one batch, but please use your judgement.
Meanwhile to finish, heat a small skillet and then add the oil. When it is almost smoking, add the ginger and scallion and stir-fry for 1 minute. Remove from the heat and stir in the soy sauce. Drizzle the mixture over the finished dumplings. Serve hot.
Once assembled, the dumplings can be covered with plastic wrap and refrigerated for several hours.They can be cooked straight from the refrigerator.
For longer storage, freeze them on their baking sheet until hard (about 1 hour), transfer them to a zip-top freezer bag, seal well, and keep them frozen for up to 1 month. Partially thaw, using your finger to smooth over any cracks that may have formed during freezing, before cooking. Previously frozen dumplings may require a few extra minutes to cook.