First, marinate the chicken. Cut the breasts into small long strips, then put them in a bowl. Add the remaining ingredients, combine well then set aside.
While the chicken is resting, prepare the veggies. Peel then slice the onion and garlic. Chop the chilli, if used.
Cut the carrot and bell pepper into small cubes, then thinly slice the cabbage.
Heat a wok, then stir-fry the chicken for 3-5 minutes, add the marinade and cook for another couple of minutes. Remove them to a bowl, including the jus.
Heat the oil in the wok, then stir-fry the onion, chilli and garlic for a couple of minutes, then add the carrot and red pepper bits. Stir-fry for 3 minutes, then add the soy sauce, Mirin and rice vinegar.
Stir, then add some water, the green beans and cabbage. Put a lid on and turn down the heat.
Cook for 5 minutes, then add the beansprouts and cook for 2 more minutes.
When the veggies are tender, put back the chicken and the jus and warm through.
Serve with sesame seeds scattered on top.