Prepare the noodles: Cook or soak the wide rice noodles according to the package directions until just tender. Drain well and set aside.

Mix the sauce: Combine light soy sauce, dark soy sauce, oyster sauce, fish sauce, brown sugar, and water in a small bowl. Stir until combined.

Heat the wok: Place a large wok or heavy skillet over high heat and add the cooking oil.

Cook the aromatics: Add the minced garlic and sliced Thai chilies. Stir-fry briefly until fragrant, taking care not to burn the garlic.

Cook the chicken: Add the sliced chicken and stir-fry until it is cooked through and lightly browned.

Add the vegetables: Add the onion and red bell pepper. Toss over high heat until slightly tender while keeping some crunch.

Add the noodles: Add the drained noodles to the wok and toss gently with the chicken and vegetables.

Add the sauce: Pour the prepared sauce over the noodles and continue tossing until the sauce evenly coats everything.

Finish with basil: Turn off the heat and add Thai basil and green onions. Toss until the basil is just wilted.

Serve immediately: Transfer the hot noodles to serving plates and enjoy while the noodles are glossy and fragrant.