Prep the noodles: If using fresh rice noodles, separate the strands gently and toss with 1 tsp oil to prevent sticking. If using dried noodles, soak or parboil according to package instructions until just pliable, then drain well.

Mix the sauce: In a small bowl, combine oyster sauce, dark soy, light soy, fish sauce, sugar, and water. Stir until the sugar dissolves. Taste and adjust sweetness or saltiness as needed.

Slice the chicken: Cut chicken thinly against the grain. Pat dry and season lightly with a pinch of salt. This helps it sear instead of steam.

Heat the pan: Use a large wok or a wide skillet. Heat 2 tbsp oil over high heat until shimmering. You want it hot enough to sear quickly.

Sear the chicken: Add the chicken in a single layer. Cook 2–3 minutes without moving too much, then stir-fry until just cooked through. Transfer to a plate to avoid overcooking.

Stir-fry aromatics: In the same pan, add garlic and chilies. Stir 20–30 seconds until fragrant. Don’t let the garlic burn.

Add vegetables: Toss in onion and bell pepper. Stir-fry 2–3 minutes until slightly tender but still crisp. You want a little bite left.

Combine noodles and sauce: Add the noodles and pour in the sauce. Toss quickly to coat. Let the noodles sit undisturbed for 20–30 seconds to pick up some smoky char, then toss again.

Finish with chicken and basil: Return the chicken to the pan along with green onions. Toss for 30–60 seconds. Turn off the heat and fold in the Thai basil so it wilts but stays bright.

Serve hot: Plate immediately. Add a squeeze of lime and a pinch of white pepper if you like extra zing.