Soak the shiitake mushrooms in 300 ml (½ pint) boiling water for 10 minutes or until soft. Drain the mushrooms then squeeze any excess water out of them, strain the liquid through a fine sieve into a bowl to remove any grit and reserve the liquid. Remove and discard the hard stalks and thinly slice the mushrooms.
Soak the dried bean curd sheets in boiling water for 6–8 minutes or until tender, drain and roughly tear the bean curd into pieces. Soak the dried lily flowers in boiling water for 8–10 minutes, then drain. Finally, soak the vermicelli in boiling water for 1–2 minutes or until soft, then drain.
Heat the stock and reserved soaking liquid to boiling point in a saucepan. Add the soy sauce, bean curd, lily flowers and mushrooms and cook for 2–3 minutes. Add the noodles and cook for another 2–3 minutes, stirring frequently. Taste and adjust the seasoning.
Spoon into a serving bowl and garnish with chopped celery leaves.