Cut sirloin beef cross grain into thin slices. Transfer beef into a zip lock bag
Mix water and baking soda together in a small bowl, then pour into zip lock bag. Let beef sit in the mixture for 30 minutes.
Mix oyster sauce, soy sauce, rice wine, sesame oil, sugar, salt, white pepper, corn starch into a bowl. Set aside.
Cut scallions into 2-inch sections. Remove skin from 2-inch ginger root, and thinly slice ginger root.
Add vegetable oil to wok. Heat wok on high heat.
When wok heats up (1-2 minutes), add ginger into wok and stir for 5-10 seconds until fragrant. Avoid burning.
Add beef to wok, cook for 30 seconds. Keep stirring well to ensure beef is evenly cook. Add sauce to beef, and stir for another 30-60 seconds. At this point, some of the beef should still have a slight pink center.
Add scallions into wok just before beef is completely cook - beef should still be slightly pink-ish or red-ish. Keep stirring and cook for another 30-60 seconds, or until beef is cooked. Beef cooks quickly! Avoid overcooking beef.
Once beef is cooked (no pink center), remove ginger scallion beef from wok promptly. Dish onto plate. Serve and enjoy!