Cut the chicken into bite-sized pieces and season them lightly with salt and pepper.

In a large skillet, heat the cooking oil over medium-high heat. Add the chicken and sauté for about 5-7 minutes until golden brown and cooked through.

Remove the chicken and set aside.

In the same skillet, add the minced garlic (and grated ginger, if using) to the remaining oil, and sauté for about 30 seconds until fragrant.

Pour in the light soy sauce, dark soy sauce, brown sugar, and a splash of water; stir well and let it simmer until bubbling and slightly thickened.

Mix the cornstarch with 2 tablespoons of water to create a slurry. Stir this into the sauce and cook for 1-2 minutes until it thickens.

Add the cooked chicken back into the skillet, tossing it to coat well in the sauce.

Incorporate the cooked noodles into the pan, mixing until they are well combined with the sauce.

Drizzle the sesame oil over everything and give it a final toss to combine.

Serve hot, garnished with chopped green onions and a sprinkle of sesame seeds.