Finely chop the mushrooms. Also mince the ginger and finely chop the scallions, separating the green and white parts.
Heat 1 tablespoon oil in a wok over medium heat. Cook the shiitake mushrooms until caramelized, about 4-5 minutes (don’t stir too often; give the mushrooms a chance to caramelize). Don’t overcook the mushrooms, or they’ll turn dry. Set aside and cool completely.
In a large mixing bowl, add the ground pork, chopped scallion whites, minced ginger, Shaoxing wine, light soy sauce, dark soy sauce, sugar, sesame oil, and white pepper. Mix it all together, and whip everything in one direction for 5 minutes. While you’re whipping the filling, add the water 1 tablespoon at a time, until the filling becomes a thick paste, with no standing liquid.
Add the cooled shiitake mushrooms, and keep stirring in one direction for another 3 minutes, until everything is well-combined.
Assemble the dish:
Take each gluten ball, and use a chopstick to poke a hole at a thin/soft spot without penetrating through to the other side. With care, use two chopsticks in a turning motion to make the opening bigger, about 3/8” in diameter and no more than ½”. Use the chopsticks to gently deconstruct the inner “structure” of the gluten ball to make room for the filling, while keeping it intact.
Stuff the gluten ball with the filling a little at a time until there is no more room, all the while keeping the gluten ball whole. Repeat until all are stuffed. This step definitely takes patience and care!
At this point, you’ll have filling left over. However, by now, the filling already inside the gluten balls will have moistened and further broken down the inner structure, creating space for more filling. So repeat the above step and stuff more filling into each ball. You should be able to divide and use up all the filling. If not, pan-fry any remaining filling in a meat patty for a little snack. An under-stuffed gluten ball will not be as round after cooking, but there’s no harm done!
Heat 1 tablespoon oil in a wok over low heat. Add the sugar, ginger and scallions, and cook for 1-2 minutes, until the sugar has melted and the aromatics are fragrant.
Add the Shaoxing wine, light soy sauce, dark soy sauce, oyster sauce, 1 star anise, and 2 ½ cups water. Bring to a boil, and then reduce the heat to medium.
Add the stuffed gluten balls, with the openings facing down. Cover, bring to a boil, and reduce the heat to medium low. Simmer for 10 minutes, carefully flipping the gluten balls halfway through the simmering process to ensure they’re cooked evenly.
After 10 minutes, flip the gluten balls so the openings face down once again. Turn up the heat to reduce the sauce. Once the sauce has become a thin gravy (you should have about 3/4 cup of sauce left in the wok), turn off the heat and serve. Garnish with the green parts of the scallions you reserved.