Step 1: Prepare the Noodles

1. Bring a large pot of water to a boil. Cook the lo mein noodles according to the package instructions until al dente.
2. Drain the noodles, rinse them under cold water to stop the cooking process, and toss with 1 teaspoon of sesame oil to prevent sticking. Set aside.

Step 2: Marinate the Beef

1. In a mixing bowl, combine the thinly sliced beef with cornstarch. Toss to coat evenly. This helps tenderize the meat and creates a nice crust when cooked.
2. Let the beef sit for 10 minutes while you prepare the vegetables and sauce.

Step 3: Make the Sauce

1. In a small bowl, whisk together soy sauce, oyster sauce, hoisin sauce, sesame oil, sugar, garlic, and ginger. Set aside.

Step 4: Cook the Beef

1. Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat.
2. Add the beef in a single layer and let it sear for 1–2 minutes without stirring to develop a nice crust. Stir-fry for another 2–3 minutes until browned.
3. Remove the beef from the skillet and set aside.

Step 5: Stir-Fry the Vegetables

1. In the same skillet, heat the remaining tablespoon of vegetable oil. Add the bell pepper, broccoli, snap peas, and carrots. Stir-fry for 3–4 minutes until the vegetables are tender-crisp.

Step 6: Combine Everything

1. Return the cooked beef to the skillet and pour in the prepared sauce. Stir well to coat the beef and vegetables.
2. Add the cooked noodles to the skillet and toss everything together until the noodles are evenly coated in the sauce and heated through.
3. Adjust the sauce consistency with water if needed.

Step 7: Garnish and Serve

1. Transfer the Beef Lo Mein to serving plates. Garnish with sliced green onions.
2. Serve immediately and enjoy!