Halve, pit and slice the plums. Set aside. Put the noodles into a heatproof bowl, then cover with boiling water and leave to stand for 10 minutes. Mix together the orange juice, cornflour, sweet chilli sauce and hoisin sauce.
Heat the vegetable oil in a wok or large frying pan. Add the pork strips and stir fry over a high heat for 3-4 minutes, until browned. Add the spring onions, carrot and pepper along with the garlic and ginger. Stir fry for 3-4 more minutes.
Add the plums and stir fry for 2 more minutes. Drain the noodles and add to the wok or frying pan. Give the orange juice mixture a good stir, then add it to the pan, stirring and tossing together for a few seconds until slightly thickened. Season to taste.
Share between 4 warmed bowls or plates and serve at once.