Bento Box Chicken Lo Mein

Ingredients

• 1 pound skinless, boneless chicken breasts, cubed
• 1 medium egg
• 4 teaspoons cornstarch, divided
• 1 tablespoon sesame oil
• 1 (12 ounce) package Chinese egg noodles
• 2 tablespoons vegetable oil, divided
• 3 cups frozen stir-fry vegetables
• 2 tablespoons cold water
• 1 cup chicken broth
• 3 tablespoons soy sauce
• 3 tablespoons oyster sauce