Cook the Noodles: Boil yakisoba noodles until tender; drain and set aside.
Prepare the Chicken: Slice chicken breast into thin strips and season lightly with salt and pepper.
Stir-Fry Chicken: In a hot pan with oil, cook chicken strips until browned and fully cooked.
Sauté Vegetables: Add shredded cabbage, carrots, and onions to the pan; stir-fry until softened.
Combine with Noodles: Toss cooked noodles into the pan with chicken and vegetables.
Add Yakisoba Sauce: Pour yakisoba sauce over the mixture, stirring to coat everything evenly.
Cook Until Hot: Continue to stir-fry until the sauce thickens and everything is heated through.
Garnish: Top with sliced green onions, pickled ginger, and sesame seeds for added flavor.
Serve Hot: Plate the yakisoba chicken and enjoy immediately while it's hot and savory.