Cook the egg noodles according to package instructions. Drain and set aside.
In a large skillet or wok, heat the vegetable oil over medium-high heat. Add the sliced beef and cook until browned, about 3-4 minutes. Remove the beef from the skillet and set aside.
In the same skillet, add the minced garlic and stir-fry for about 30 seconds until fragrant.
Add the broccoli, bell pepper, and carrots to the skillet. Stir-fry for 4-5 minutes until the vegetables are tender-crisp.
Return the cooked beef to the skillet. Add the cooked noodles, soy sauce, oyster sauce, sesame oil, sugar, salt, and pepper. Toss everything together and cook for an additional 2-3 minutes until heated through.
Serve hot, garnished with chopped green onions.