2 tbsp sesame oil
1 onion, halved and finely sliced
2 garlic cloves, finely sliced
2 tbsp finely sliced ginger
2 litres beef stock
180-200g beef, sliced thinly
200g packet of udon noodles
Choy sum or bok choy
2 cups sliced Chinese cabbage
1 small red capsicum, sliced finely
Fresh coriander leaves, sliced green chilli, crushed salted peanuts, and lime halves for squeezing, to serve