Prepare the Pork: Cut the pork tenderloin in half lengthwise, then slice crosswise into ⅛-inch-thick strips. In a medium bowl, combine pork, water, and baking soda. Toss to coat and let sit for 5 minutes.
Prepare the Sauce: In a small bowl, mix grated ginger with 1 tablespoon vegetable oil; set aside. In another small bowl, whisk together chicken broth, oyster sauce, 2 ½ teaspoons Shaoxing wine, sesame oil, rice vinegar, and ½ teaspoon cornstarch; set aside. In a separate bowl, combine soy sauce, remaining ½ teaspoon Shaoxing wine, and remaining ¼ teaspoon cornstarch with the pork; toss to coat.
Stir-Fry the Pork: Heat 2 teaspoons vegetable oil in a 12-inch nonstick skillet over medium-high heat until just smoking. Add pork and increase heat to high, cooking while tossing slowly but constantly until no longer pink, about 2 to 6 minutes. Transfer to a clean bowl.
Stir-Fry the Vegetables: In the same skillet, heat the remaining 2 teaspoons vegetable oil over high heat until just smoking. Add asparagus and red bell pepper, cooking while tossing constantly until tender and slightly browned, about 2 to 6 minutes.
Combine Flavors: Push vegetables to one side of the skillet and reduce heat to medium. Add the ginger mixture to the cleared side and mash it into the skillet until fragrant, about 30 seconds. Stir the ginger mixture into the vegetables.
Finish with Sauce: Whisk the broth mixture to recombine and pour it into the skillet along with the pork and any accumulated juices. Increase heat to high and cook, stirring constantly, until the sauce thickens, about 30 seconds.
Serve: Sprinkle with sliced scallions and serve immediately.