First, make the dipping sauce. Whisk soy sauce, Sriracha, and lemon juice together. Set aside until ready to serve.
To begin the dumplings, take half of the bunch of scallions and chop completely (whites and greens). Set the other half aside for garnish. Add sesame oil to a saute pan and heat over medium-high. Once hot, add garlic, ginger, and chopped scallions. Cook until fragrant, about 1 minute. You just want to remove the raw taste from the ingredients, not fully cook them. Remove from heat and set aside.
Add ground pork, hoisin sauce, soy sauce, Chinese five spice (if using), and egg in large bowl with sauteed mixture. Using a wooden spoon (or even your hands), combine mixture until uniform.
Grab your wonton wrappers. Place about 1 1/2 teaspoons of pork mixture into the center of each dumpling. Brush a little water around the edge of the wonton with your finger. Seal the dumpling shut by pinching the sides together, making sure to get all the excess air out.
Once the dumpling is shut and sealed, create the pleats using your thumb and forefinger. You should have a cute little purse when you're done. Set the dumpling flat on some flour (so it doesn't stick). Repeat with the rest of the wonton wrappers.
Heat a large saute pan with 1 tablespoon of vegetable oil over high heat. Place half of the dumplings into hot oil and fry for 1 to 2 minutes. Remove and drain over paper towels. Repeat with second tablespoon of oil and remaining dumplings. Reduce heat to medium-high.
Place first batch of dumplings back into saute pan. Add 1/2 cup of water so that it rises up the dumplings about halfway. Cover dumplings and let them cook/steam for 5 to 7 minutes. Remove and repeat with second batch.
Chop remaining scallions and garnish dumplings with them. Serve immediately with Sriracha Soy Sauce and enjoy!