Cook the egg noodles according to package instructions. Drain and set aside.
In a bowl, combine the sliced beef, 1 teaspoon soy sauce, and cornstarch. Mix well and let marinate for about 15 minutes.
Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the marinated beef and stir-fry for about 3-4 minutes until browned. Remove the beef from the skillet and set aside.
In the same skillet, add the broccoli, bell peppers, and carrots. Stir-fry for about 5 minutes until the vegetables are tender-crisp.
Add the garlic and cook for an additional minute until fragrant.
Return the beef to the skillet and add the cooked noodles, oyster sauce, 1 tablespoon soy sauce, and hoisin sauce. Toss everything together and cook for another 2-3 minutes until heated through.
Season with salt and pepper to taste. Garnish with chopped green onions before serving.