It depends where the flight is catered. For the SYD-Asia leg, it would be catered in Sydney and come from Lewis's catering. I had one a few weeks ago in business class and it was excellent IMO - complete with menu, and quite closely matched to the regular menu. Starter of smoked salmon + salad, then a salad, main of beef, cakes etc etc. Much better than they used to be. Snack was also good (chicken salad), and they had some deicious nougat and biscuits.In economy you would get a similar meal to regular pax.
For the BKK-LHR segment, the meal was catered in Bangkok and was OK, but it was the same as economy class and breakfast was continental.