Toss the beef with the baking soda, cornstarch, soy sauce, Shaoxing wine, and oil. Marinate 20 minutes (the baking soda is the restaurant trick for tender beef — rinse it off if you marinate longer than 30 min).
Cook the noodles 1-2 minutes under package directions, rinse under cold water, drain, and toss with a drizzle of sesame oil so they don't stick.
Heat a wok or your biggest pan over the highest heat until it just smokes, with a thin film of neutral oil. Sear the beef in batches, about 2 minutes, without crowding. Pull it out and set aside.
In the same pan, fry the garlic 15 seconds, then add the onion, carrot, cabbage, and mushrooms. Stir-fry about 2 minutes, keeping everything crisp. Stir in the bean sprouts last.
Add the beef and noodles back to the pan, pour the sauce over everything, and toss hard until the sauce thickens and coats everything glossy. Add the scallion greens and a final drizzle of sesame oil. Serve immediately.