Marinate the chicken in teriyaki sauce for 20 minutes. Drain the chicken but keep the marinade.
Add 1 tbsp of the sunflower oil to a wok/frying pan and stir fry the chicken for 2-3 minutes until sealed. Set aside.
Add the remaining oils and fry the onion, mushrooms, broccoli and red pepper for 2 minutes. Return the chicken and marinade to the wok, add a little water. Cook for 1-2 minutes until chicken is cooked. Serve with rice noodles and toasted sesame seeds.