Prep the veggies: julienne the carrot, mince the garlic and ginger (if not using paste) and roughly chop the onion, the cabbage and the white part of the scallions (spring onions). Thinly slice the green part and set aside for garnish.
In a large bowl, soak the noodles in cold water for 10 minutes until softened. Drain and cut with scissors into shorter pieces, if needed.
In a small bowl, whisk together both soy sauces and mushroom sauce, vinegar, sugar, spices & powders, water/stock. This will be the stir-fry sauce.
Heat a wok or large skillet over high heat until a drop of water evaporates immediately on contact. Add cooking oil and swirl around to evenly coat the sides. Stir-fry the garlic, ginger, and white parts of spring onions until aromatic, about 30 seconds. Toss in the cabbage and julienned carrots, and stir-fry continuously for 2 minutes, until vegetables are slightly wilted.
Give the sauce a stir and pour it into the wok. It should sizzle as it hits the hot surface.
Add the noodles and continue to cook, stirring constantly and folding the noodles over with your spatula, until liquid is mostly absorbed. If the noodles are cooking too quickly, reduce the heat— you don't want them to dry out and stick to the bottom.
Switch off heat. Stir in sesame oil and additional salt if needed. Scatter on the green part of the spring onions saved for garnish and serve immediately.