Heat oven to 220C/200C fan/gas 7. Rub the duck leg all over with five-spice and seasoning, place on a baking tray and roast for 25 mins.
Meanwhile, cook the rice noodles following pack instructions. Drain and cool under cold running water, then drain again well and toss with the celery, carrot, cucumber and spring onions. When cool enough to handle, remove the duck meat and crispy skin from the bone and finely shred.
To make the dressing, mix the hoisin and soy sauce with 2 tbsp water. Divide the noodles between two plates and top with the shredded duck. Drizzle over the dressing and serve.