Cook the instant noodles as per the packet directions. Drain and set aside. Mix the flavour sachets together in a separate small bowl and set aside.
Meanwhile, heat half of the oil in a non-stick frying pan over medium heat. Add the chicken and cook until just cooked through and lightly golden. Don't overcook. Remove from the pan and set aside to rest. It will continue to cook through as it rests without drying out.
Heat the remaining oil in the same frying pan and heat on high. Add the vegetables and stir fry for 2-3 minutes until they are brightly coloured. Add the chicken back to the pan. Add the noodles and flavouring. Toss to combine.
Divide into bowls or containers and serve immediately or refrigerate to eat later.