Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Add the sliced chicken and season with salt and pepper. Cook for about 5-7 minutes, or until the chicken is cooked through and no longer pink. Remove the chicken from the skillet and set aside.

In the same skillet, add the remaining tablespoon of vegetable oil. Add the bell peppers, broccoli, and snap peas. Stir-fry for about 3-4 minutes until the vegetables are tender-crisp.

Add the minced garlic and ginger to the skillet, stirring for about 30 seconds until fragrant.

Return the cooked chicken to the skillet. Add the cooked egg noodles, soy sauce, oyster sauce, and sesame oil. Toss everything together until well combined and heated through.

Stir in the cornstarch mixture and cook for an additional minute until the sauce thickens slightly.

Remove from heat and garnish with sliced green onions and sesame seeds if desired. Serve immediately.