Place the mushrooms in a bowl with the cornflour and toss to coat. Set aside.
Heat the oil in a wok over a high heat until the oil starts to shimmer. Add the ginger, garlic and salt and stir quickly, then add the mushrooms, red peppers and pak choi and stir-fry for 2–3 minutes until just tender.
Stir in the rice wine, soy and sweet chilli sauces and spring onions and cook for 1 more minute, until the sauce has thickened.