spring onions are in fact very young onions, harvested before the bulb has had a chance to swell. Both the long, slender green tops and the small white bulb are edible, and are good either raw or cooked. They have a similar flavour to onions, but are much milder.
The red cabbage is a kind of cabbage, also known as purple cabbage, red kraut, or blue kraut after preparation. Its leaves are coloured dark red/purple.