1. Cook the Lo Mein noodles according to the package instructions. Drain and set aside.
2. Heat the vegetable oil in a wok over medium-high heat. Add the garlic and stir-fry for 30 seconds.
3. Add the beef slices and cook until browned. Remove from the wok and set aside.
4. In the same wok, add the bell pepper and carrot. Stir-fry for 3-4 minutes until tender.
5. Return the beef to the wok, add the cooked noodles, soy sauce, oyster sauce, and sesame oil. Toss everything together until well combined and heated through.