Fish Fragrant, but Neither

Yuxiang Rou Si ("Fish-fragrant" Pork Threads)
Serves 2-3

vegetable oil
3/4 pound pork, cut into 1-inch-long matchsticks
1/2 pound mushrooms, plus 1/2 pound other (bamboo shoots etc)
2 tablespoon Chili Sauce
1 tablespoon minced fresh ginger
2 tablespoons minced garlic
3 tablespoons soy sauce + 1 tablespoon fish sauce
1 tablespoon brown sugar
1 tablespoon vinegar
4 (small) scallions, chopped
Slurry

Brown the pork, then remove and reserve.
Stir-fry the vegetables for 1 minute. Add the chile sauce, ginger, and garlic, and stir-fry for another 30 seconds.
Add the soy sauce, sugar, vinegar, reserved pork, and scallions.
Mix, lower the heat, cover, and simmer for 2-3 minutes. Thicken with slurry, if needed.