Cut beef against the grain (see picture illustrations above) into about ⅛ inch thick x ½ inch wide x 2 inch long slices.
Transfer sliced beef to a bowl, add salt, sugar, light soy sauce, dark soy sauce, oyster sauce, black pepper, and baking soda to the beef. Mix by hand until the color (from dark soy sauce) looks evenly on the beef. Add ½ egg white to the beef. Mix well by hands for about 2 minutes until all the egg white has been absorbed into the beef.
Add cornstarch to the beef. Mix gently by hands until all the beef slices are evenly coated with a thin layer of cornstarch.
Add olive oil to the beef. Mix gently by hands until all the beef slices are evenly coated with a thin layer of olive oil. (This step can prevent the beef slices from sticking to each other in the frying pan.) Set aside to marinate for 10 minutes.
Add all the sauce ingredients to a small bowl. Mix well until all the ingredients are dissolved. Set aside.
Add 1 tbsp of vegetable oil to a large frying pan, heat up the oil over medium high heat. (See Note 1 Below) Add marinated beef slices to stir fry for 2-3 minutes until it is browned. Remove the beef from the frying pan and set it aside.
In the same frying pan, add the minced garlic, wedged onion, and bean sprots. No additional oil is required at this stage; simply utilize the residual oil from frying the beef. Stir-fry for 1-2 minutes until slightly softened. Remove the vegetables from the frying pan and set it aside.
In the same frying pan, heat 1 tbsp of vegetable oil (See Note 2 Below). Add the rice noodles (see my homemade rice noodles recipe here), gently spread out with chopsticks or a pair of silicone tongs. Gently stir-fry the rice noodles over medium high heat for 1-2 minutes. Alternatively, you can use the technique of wok tossing to prevent the rice noodles from breaking apart during the cooking process. Add the cooked vegetables back into the frying pan. Pour the prepared sauce over the noodles and vegetable. Toss the noodles and vegetables until they are evenly coated with the sauce.
Add the cooked beef together with sliced green onions back into the frying pan and toss everything together over medium heat for another 1-2 minutes until all the ingredients are heated through.
Add more salt or soy sauce to taste if desired. Remove from heat and transfer out to two serving plates. Serve hot.