Start by marinating the beef. Combine 2 tablespoons of soy sauce, 1 tablespoon of oyster sauce, 1 teaspoon of sugar, 1 teaspoon of cornstarch, and 1/2 teaspoon of sesame oil in a bowl. Add the 1/2 pound of thinly sliced beef and ensure every piece is well coated. Set it aside for at least 15 minutes to absorb all the flavors. Meanwhile, boil 8 ounces of fresh egg noodles according to the package instructions, drain, and set them aside.
Heat 2 tablespoons of vegetable oil in a large pan over medium-high heat. Add 2 cloves of minced garlic and 1 teaspoon of grated ginger, letting their rich aroma fill the air for about 30 seconds. Toss in the cooked egg noodles and stir-fry them for 2–3 minutes until they become golden and slightly crispy. Add 2 cups of mixed vegetables and 1 cup of bean sprouts, cooking for an additional few minutes. Sprinkle with salt and pepper, and garnish with 2 chopped green onions.
Using a separate pan, heat a small amount of vegetable oil over high heat. Add the marinated beef slices, searing for about 1–2 minutes on each side until nicely browned and perfectly cooked. Transfer the beef to a plate and set it aside.
Plate your crispy noodles and top them with the perfectly seared beef slices. Add a final touch by garnishing with fresh green onions. Your dish is ready to enjoy!