Mix cornflour and dark soy until lump free, then add remaining Sauce ingredients.
Transfer 2 tsp Sauce into bowl with chicken. Toss to coat.
Heat oil in a wok or large heavy based skillet over high heat until smoking.
Add onion and garlic, stir 30 seconds.
Add chicken, stir until white on the outside, still raw inside - 1 minute.
Add carrot and capsicum/bell peppers, cook 2 minutes or until chicken is cooked.
Add noodles, Sauce and water. Use 2 wooden spoons and toss for 30 seconds.
Add green onions, toss for another 1 minute until all the noodles are slick with sauce.
Serve immediately, garnished with extra green onions if using.