Mix the teriyaki sauce, five-spice and curry powders. Add half to the pork, turning to coat, and leave to marinate for 15 mins.
Heat oven to 200C/180C fan/ gas 6. Remove pork from the marinade and put on a small baking tray lined with foil. Roast for 15-20 mins.
Meanwhile, cook the noodles following pack instructions, but reduce the cooking time by 1 min. Refresh in cold water and drain very well.
Transfer the pork to a chopping board and rest for 5 mins. Set a large non-stick frying pan or wok over a medium-high heat. Add the oil and stir-fry the veg for 3-4 mins. Cut the pork in half lengthways, then thinly slice. Tip into the pan, with the prawns, noodles and remaining marinade. Toss together for 2-3 mins until hot.