Cook the noodles in simmering water with a drizzle of soy sauce as per pack instruction and keep warm until needed.
Meanwhile, place a wok over high heat and preheat for 2 minutes or so.
Drizzle the oil and add the vegetables. Cook for 2 minutes until coloured, stirring to ensure it catches colours.
Add the chicken pieces, and again, stir-fry for a further 1-2 minutes, shaking the pan to ensure all the vegetables are getting some heat and sear.
then, add some water and add the lid. Let the mixture cook with the lid on for 1-2 minutes
then, add the prawns, and katsu sauce. Add a drizzle extra of water , lime juice and soy sauce if needed.
Toss to coat and flavour the vegetables and place the lid back for a further minute or until the prawns are cooked through.
Remove the lid. check the seasoning and adjust if needed.
Add the noodles to the wok to toss again to combine. Transfer onto a serving dish and enjoy immediately with the fresh cucumber ribbon and extra lime juice.