Soak the rice noodles in warm water for about 30 minutes until soft.
Drain and keep warm
Soak the sliced onion rings in lemon juice an let stand for 30
In four large bowls place a quarter of the mint, bok choy, lemon
wedges into each
Soak the noodles for 30 minutes in warm water, until just soft.
Drain and keep warm. Soak the onion rings in the lemon juice for 20
In a large saucepan bring the beef stock to the boil
Drop bok choy into stock and cook for one minute then remove
In four large bowls put a quarter of the noodles, fish sauce,
chillies, onions, and herbs.
Put a quarter of the raw beef into each bowl and cover with the beef
Serve at once