Heat vegetable oil in a wok until smoked. Mix the light soy sauce, oyster sauce, green onion, ginger, pork and the hot oil in a large bowl.
Add tofu, black fungus, vegetables, salt, sugar, sesame oil, and chicken essence in the bowl and mix well with the pork mixture to make the dumpling filling.
Add flour in a large bowl. Slowly pour the water into the flour and mix them with a spoon. Transfer the dough to the working surface and knead it until the surface becomes smooth. Let the dough rest for about 30 minutes.
Divide the dough into 12 to 14 grams small doughs evenly and press it to a round disc.
Scoop about 1 tablespoon of dumpling filling and place it in the center of the wrapper. And make the wrapper completely wrap the filling into a dumpling.
Put the tofu dumplings in the steamer. Steam it for about 9 minutes. Turn off the fire and keep warm for 5 minutes. Transfer it on a plate. Serve.