I grow green pak choy, flowering pak choy, and chinese water spinach. We grow it for ourselves and for our birds as it beats going and buying greens for them. All are easy to grow, especially if you live in a warm climate. We also grow some chinese kale for then and some corn for treats. As we sell seeds for all these on
Ebay, it's really no problem growing our own as well, and as I live in Thailand now, I'm used to eating all these greens myself as they are staples across here.
My birds, ducks and chickens, also love eating banana leaves and stems.
It's great to see because at least I know my chickens are all on a healthy diet, and I do believe this gets passed on via eggs and meat.