Last year, I saw a video about harvesting cabbage, in which the master gardener said that one should not just pull the plants up roots and all, but should cut the cabbage off and leave the bottom part in the ground. He said new leaves would grow. These would not grow into heads of cabbage, but would be like baby cabbage leaves. I tried this and it was working until the slugs decided the new leaves made for tasty munching!
A few weeks ago, I got a small head of pointy cabbage from veg man and when I was cutting it up, I noticed the base and thought, 'Hmm, I wonder what would happen if I stuck this in water.' I am a big fan of regrowing stuff and utilising everything to its fullest extent, so I went into our (unused except for storage) dishwasher, pulled out a container, put some water in the bottom, and plunked in the cabbage base.
I am happy to report that when we returned from our jaunt to southwest Donegal the other day, there were some lovely, deep green, wee leaves growing out the side.