Make the filling. In a large mixing bowl, combine 1 lb ground pork, ½ lb chopped shrimp, sliced scallions, 3 Tbsp soy sauce, 2 Tbsp sesame oil, 1 Tbsp grated ginger, 2 tsp rice vinegar, 1 tsp sugar, ½ tsp pepper, and 1 large egg white. Mix thoroughly until the filling looks cohesive and slightly sticky, about 1-2 minutes. The mixture should feel tacky—this helps the wontons stay juicy and hold together when cooked.
Stuff the wontons. Line a baking sheet with parchment paper. Working with one wrapper at a time, place on a clean surface, then spoon about 1 tablespoon of filling into the center. Dip your finger in water and lightly moisten the edges. You can fold into a neat pattern, but I take the easier approach of scrunching the wrapper up around the filing to create a rustic seal. Transfer to the prepared baking sheet and repeat with remaining wrappers.
Prepare the chili oil. In a heatproof bowl, combine sliced scallions, 2 chopped cloves of garlic, 1 Tbsp crushed red pepper flakes, and 1 Tbsp sesame seeds.
Heat the oil. In a small saucepan, heat ¼ cup vegetable oil over medium heat until shimmering (about 2-3 minutes). It should be hot but not smoking. Carefully pour the hot oil over the scallion mixture. It should sizzle immediately and bloom the aromatics.
Finish the sauce. Stir in ¼ cup soy sauce, 3 Tbsp rice vinegar, 2 tsp oyster sauce, and 1 tsp sugar. Mix well and allow to cool slightly before serving.
Boil the wontons. Bring a large pot of water to a gentle boil. Working in batches so you don’t overcrowd the pot, add wontons then cook for 3-4 minutes, or until they float and the filling is cooked through. Use a slotted spoon to transfer to a serving platter or shallow bowl.
Serve. Spoon or pour the chili oil generously over the top (or serve alongside for dipping). Finish with thinly sliced scallions and a sprinkle of sesame seeds. Enjoy!