In a bowl, combine the sliced chicken breast with cornstarch and 1 tablespoon water. Toss well until coated.
Cook the noodles according to the package instructions. Drain and toss with sesame oil to prevent sticking.
In a small bowl, whisk together soy sauce, oyster sauce, dark soy sauce, honey, and minced garlic.
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 and fully cooked.
Pour the prepared sauce into the pan and simmer for 2–3 minutes until it becomes thick and glossy.
Add the cooked noodles and toss thoroughly to coat every strand with the sauce.
Sprinkle in chili flakes if using.
Stir in the sliced spring onions.
Serve the Sticky Garlic Chicken Noodles hot, garnished with sesame seeds.