Thinly slice the onion, garlic, chilli and ginger.
Dice the courgette and cut the mushrooms & red pepper into slices or chunks.
Heat the oil in a wok and stir-fry the onion for 5 minutes, then add the garlic and ginger and stir-fry for 30 seconds.
Add the chopped vegetables and stir-fry for 3 minutes or so, then add the soy sauce, Mirin and vinegar. Turn down the heat, put a lid on and cook for another 5 minutes or until the vegetables are cooked through.
Meanwhile, cook the noodles according to the packet instructions, then drain.
When the vegetables are cooked, add the noodles and the miso paste. Turn off the heat and stir to combine.
Serve with sesame seeds and coriander leaves scattered on top.