Thinly slice beef loin. In a bowl, add the beef, ginger, ½ teaspoon salt, ¼ teaspoon sugar, 1 teaspoon soy sauce, 2 tbs water, 1 tbs olive oil, and ½ tbs corn starch. Mix together and marinate for 30 minutes to 1 hour (overnight is best!).
Start prepping for the noodles. Slice white onion and chop green onions 3 inches lengthwise. Wash and dry bean sprouts.
Heat large wok or pan on high. Once it starts smoking, add oil and then, add the beef. Stir fry for 2-3 minutes until the beef is golden brown. Be careful it might splatter. Set aside on a plate.
In the same wok (on high heat still), stir fry white onions and bean sprouts for 1 minute.
Then, add your rice noodles. Fry for one minute and keep stirring. Then, add soy sauce, dark soy sauce (for color), salt, and sugar. Mix together.
Immediately add the cooked beef back in the rice noodles. Mix together and cook for 2-3 minutes. Don’t cook for too long or the noodles will soften and be mushy. Hope you enjoy!