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 chicken and cook for about 5-7 minutes, or until the chicken is cooked through and no longer pink.
Add the broccoli, red bell pepper, and carrots to the skillet. Stir-fry for about 3-4 minutes, or until the vegetables are tender-crisp.
Pour the teriyaki sauce over the chicken and vegetables, stirring to coat everything evenly. Cook for an additional 2 minutes to heat through.
Add the cooked egg noodles to the skillet, tossing everything together until well combined and heated through.
Serve hot, garnished with sliced green onions and sesame seeds if desired.