Heat oil in a deep wide wok and saute ginger, garlic and onions till they get lightly brown. Add in mushrooms and fry for a few minutes till all the moisture evaporates and it starts to brown slightly.
Toss in carrots, cabbage and peppers, and stir-fry for a few minutes. Add in white pepper and toss well.
Drain noodles from the cold water, and add it into the wok along with sauces and salt & pepper. Toss well so that the noodles, veggies and sauces are well mixed.
Garnish with spring onions and serve warm.