1. In a small saucepan, add vinegar and sugar, stir over heat until sugar dissolves, set aside.
2. Peel and thinly slice ginger, place in a bowl, add salt and a bit of water, wash briefly and drain.
3. Soak ginger in sugar vinegar mixture for 15 minutes, drain.
4. Meanwhile, soak noodles in hot water for 2-3 minutes, until just soft; separate noodles, drain.
5. Skin and thinly slice duck breast place in a bowl with egg white, corn starch and light soy sauce. Set aside.
6 For the sauce, combine ingredients in a bowl and mix well, season to taste.
7. Place a wok on high heat, pour in oil, heat oil until almost smoking, add duck and slightly fry. Set duck aside, pour oil into a heat-proof bowl; except for about 1 tablespoon left in wok.
8. Heat remaining 1 tablespoon of oil in wok until hot but not smoking; add garlic, chilli, ginger and stir fry for 20 seconds, then add pineapple and stir fry for 30 seconds. Add duck pieces and Chinese wine and stir fry for 20 seconds.
9. Add noodles and sauce, stirring continuously until well combined,
add spring onion. Check seasoning and adjust if necessary. Serve.