Instructions
Step 1
In a small skillet set over low heat, toast the sesame seeds, stirring frequently, until lightly golden brown, 3–5 minutes. Remove from the heat.
Step 2
In a mortar and pestle or food processor, grind the sesame seeds, almonds, and walnuts to the texture of fine sand. Transfer to a medium bowl and add the sugar, shortening, and 2 tablespoons of water; stir well to form a paste.
Step 3
In a large rimmed tray, spread enough of the flour to form an approximately ¼-inch layer. Using your palms, roll the sesame seed mixture into small balls (¼ –½ inch in diameter), space them out on the tray, and shake the tray until all the balls are evenly coated in flour. Transfer the balls to a second large rimmed tray and sprinkle with water until the balls are moist. Add more flour to the first tray until the layer is again ¼-inch deep, and transfer the balls back to the first tray. Repeat until all the flour is coating the balls. (This could take as many as 10 rounds. As the dumplings get larger, you may want to divide them onto 2 additional trays so they have enough room to roll around.)
Step 4
Cook the dumplings: Bring a large pot of water to a boil over high heat. Gently drop in the dumplings and cook, stirring frequently to prevent them from sticking to the bottom of the pot, until most of them float to the surface, about 5 minutes. Add 1 cup of cold water, bring to a boil again, and cook until the dumplings look slightly translucent, about 3 minutes. Use a slotted spoon to transfer the dumplings to serving bowls, then use a ladle to pour 1–2 cups of cooking water into each bowl. Serve warm.