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 breast and cook until browned and cooked through, about 5-7 minutes. Remove the chicken from the skillet and set aside.
In the same skillet, add the minced garlic, bell peppers, carrots, and snow peas. Stir-fry for about 3-4 minutes until the vegetables are tender-crisp.
Return the cooked chicken to the skillet. Add the cooked egg noodles, soy sauce, oyster sauce, sesame oil, ground ginger, salt, and pepper. Toss everything together until well combined and heated through, about 2-3 minutes.
Stir in the chopped green onions just before serving.