In a mixing bowl, combine the sliced boneless chicken with soy sauce, cornstarch, and sesame oil. Marinate for 5–10 minutes.

Bring a large pot of water to a boil and cook lo mein noodles according to package instructions for 4–6 minutes. Drain and toss with sesame oil.

In a bowl, whisk together soy sauce, oyster sauce, hoisin sauce, brown sugar, and chicken broth until fully mixed.

Heat vegetable oil in a wok or skillet over medium-high heat. Add the marinated chicken and cook for 5–7 minutes until browned and cooked through. Remove and set aside.

In the same pan, add more oil if needed, then add minced garlic and ginger. Sauté for 30 seconds to 1 minute until fragrant.

Add bell peppers, carrots, and snap peas to the pan, stir-frying for 3–4 minutes until crisp-tender.

Return the cooked chicken to the pan and pour prepared sauce over the mixture. Simmer for 1–2 minutes until sauce thickens.

Add the cooked noodles and sliced green onions, tossing to coat everything evenly. Stir-fry for an additional 1–2 minutes. Serve immediately.