Bok choy?

What is it? What do I do with it? (Other than give it to my rabbits?)
My Mum has decided to go all natural and order stuff from our "Aussie farmers" to support them. So our apple juice tastes like syrup, our orange juice tastes like oranges. And we have bok choy. Well, Peter likes it. And after 3 days, I convinced Ruby to eat it. I still haven't tried it.