Place the sliced chicken breast in a bowl. Add cornstarch and 1 tablespoon of water, then toss well to coat evenly.
Cook the noodles according to the package instructions. Drain and toss with sesame oil to prevent sticking. Set aside.
In a small bowl, combine soy sauce, oyster sauce, dark soy sauce, honey, and minced garlic. Mix until well blended.
Heat vegetable oil in a wok or large skillet over medium-high heat.
Add the chicken and stir-fry for 4–5 minutes until golden brown and fully cooked.
Pour the prepared sauce into the pan and stir well. Allow it to simmer for 2–3 minutes until it becomes thick, glossy, and sticky.
Add the cooked noodles to the pan. Toss thoroughly so every strand is coated with the flavorful sauce. This is where the Sticky Garlic Chicken Noodles develop their signature texture and flavor.
Sprinkle in chili flakes if using.
Stir in the sliced spring onions.
Garnish with sesame seeds and serve immediately while hot.