Preheat the oven to 220 C.
Boil the noodles according to packet instructions. 2 mins before they finish cooking, add the bottom parts of the bok choy to the same pot. Drain them out together and run under cold water so the noodles don’t clump.
Separate the spring onion tops from the whites. Set aside with the bok choy tops.
Mix together all the ‘marinade & wok sauce’ ingredients in a large bowl. Tip the mushrooms in and toss with your fingers to coat. Let it sit for 10 mins.
After 10 mins squeeze out the mushrooms firmly using both your hands. Do this in small handfuls to get as much of the water out as possible. Catch the juices in a bowl and retain. This along with the remaining marinade in the bowl is your wok sauce*.
Lay the mushrooms out in a single layer on a large baking tray; few overlaps are fine. Roast for 15 mins in the top rack of the oven.
Meanwhile make the noodles: add oil to a large wok/pan and sauté the bottom parts of the spring onions, ginger, and garlic.
Once the spring onions start to colour around the edges, tip in the wok sauce* that we set aside earlier. Bump up the heat and cook until most of the water evaporates and you’re left with a sticky glaze.
Add the noodles and bok choy, bok choy tops, spring onion tops, roasted mushrooms, sesame seeds, and toasted sesame oil. Toss it all together, adjust seasoning, and serve.