Heat the oil in a wok or large frying pan. Stir-fry the red onion over a high heat for 2 minutes, then add the shredded duck and some seasoning and stir-fry for another 2 minutes.
Stir in the hoisin sauce and add the sugar snap peas, baby corn and bean sprouts. Stir-fry for 2 minutes more, adding a splash of water to help the veg cook.
Add in the rice noodles, stirring to combine and separate in the pan.
Toss everything to combine, then serve immediately, garnished with chillies if you like.