1.Place noodles in a large heatproof bowl, cover with boiling water; separate with a fork, drain.
2.Heat oil in wok; stir-fry brown onion and garlic until onion softens. Add five-spice; stir-fry until fragrant. Add mushrooms; stir-fry until almost tender.
3.Add combined sauce, stock and the water to wok; bring to the boil. Add buk choy, choy sum and green onion; stir-fry until buk choy just wilts. Add tofu and noodles; stir-fry until hot. Serve stir-fry topped with sprouts.
You can use dried rice stick noodles if fresh noodles are not available. Place dried noodles in a large heatproof bowl; cover with boiling water. Stand until just tender, then drain.Note