For the dipping sauce: Combine the soy sauce, Sriracha and lemon juice in a bowl and set aside until ready to serve.
For the pork dumplings: Heat a large nonstick skillet over medium-high heat. Add the garlic, ginger, sesame oil and scallions and cook until fragrant, 1 to 2 minutes (you just want to take the bite off of the raw ingredients, not saute them). Remove from the heat and allow to cool 1 minute.
Combine the cooked garlic, ginger and scallions with the pork, hoisin, soy sauce, five-spice powder and egg in a large mixing bowl.
Working with the dumpling wrappers, start with the floured surface facing down. Place 1 1/2 teaspoons of filling in the center of a wrapper. Wet the edge of the dumpling with water, using your finger, and fold the circle in half without sealing, like a taco. Pinch one end closed. Create pleats on one side using your thumb and forefinger, pressing against the other flat edge to seal as you go. Flatten the bottoms so they can get a nice pan fry on them. Repeat until all the dumplings are filled. Keep the dumplings on a lightly-floured sheet tray to keep them from sticking, and cover with a slightly damp towel to keep from drying out.
Heat the veggie oil over high heat in the same skillet. Working in batches, pan-fry the dumplings by placing them bottom-side down and frying until golden brown, 1 to 2 minutes.
Once the dumplings are golden brown, working carefully (it will splatter), pour 1/2 cup water into the skillet to cover the dumplings halfway. Immediately cover with a lid, leaving a small crack for steam to escape. Cook until the water has evaporated, 5 to 7 minutes. Transfer the dumplings to a paper towel-lined plate to soak up excess oil and repeat the process with the remaining dumplings.
Cook's Note: This recipe makes a lot of dumplings; just keep extra in your freezer for a late night snack!