Heat a wok over high heat. Add the walnuts & cook, stirring constantly, for 2-3 minutes or until hot. Remove & set aside.
Add oil, garlic & chilli to the wok & stir-fry for 30 seconds. Add the mushrooms & stir-fry for 2-3 minutes or until the mushrooms are just tender.
Combine the balsamic vinegar & brown sugar, add to the mushrooms & stir-fry 30 seconds or until well coated.
Remove from the heat, stir in the walnuts & lime juice. Serve with steamed jasmine rice.