Stir together the pork, shrimp, leeks, scallions, soy sauce, dark soy sauce, oyster sauce, bouillon, sugar, and black pepper in a large bowl.
Place 1 tablespoon of the pork filling on the center of 1 wonton wrapper. Using a spoon, smear the filling in an even layer across the face of the wrapper. Repeat with the remaining filling and wrappers.
Heat the oil in a large pan over medium-high heat until the oil shimmers.
Working in batches of 3 or 4 dumplings (8–10 batches total), add the dumplings to the hot oil, and cook until the bottoms are crispy and slightly charred, about 2 minutes. Flip, and cook until the wrappers crisp up, about 1 minute. Repeat with the remaining dumplings.
Serve with chili oil, black vinegar, and more soy sauce.
