Not sure on the Australia-Korea routes, but on North America-Korea, we get fed pretty well. There's almost always a western option for the main meals, but the bi-bim-bap (veggies and meat on rice) is recommended. You'll probably get hot soup at least once, either with a meal, or ramen as a snack. That always struck me as odd.

They'll have coffee and hot green or black ("English") tea available.