Loosen the yakisoba noodles gently with warm water if they are stuck together, then drain thoroughly.

Combine soy sauce, oyster sauce, Worcestershire sauce, ketchup, brown sugar, and sesame oil in a small bowl until smooth and glossy.

Heat vegetable oil in a large wok over medium-high heat until shimmering.

Add sliced chicken and cook until lightly browned with caramelized edges and no pink remaining.

Stir in onion and garlic and cook until fragrant and slightly softened.

Add shredded cabbage and carrots and toss continuously until the vegetables become vibrant and slightly tender while still crisp.

Add the noodles to the wok and gently separate them with tongs as they warm through.

Pour the sauce mixture evenly over the noodles and vegetables.

Toss everything together until the noodles are coated and glossy with deep savory aroma rising from the pan.

Sprinkle with green onions, black pepper, and sesame seeds before serving hot.