Here are two things you can do when the CSA gives you red cabbage:
Strip off the outside leaves of the head of cabbage, chop em up coarsely (swear while you're doing it, how's that for coarse). Put the chopped cabbage in a heatproof nonreactive bowl or saucepan and pour boiling water over to cover. Let sit until cool. Discard the cabbage and keep the lovely purple water.
Your purple cabbage water is a homemade pH tester! Bases turn it varying shades of blue, green, and even yellow... acids turn it pink to magenta.
Some substances we tried - dish soap, baking soda, juice, milk, coffee, oil, bug spray, lime juice, tomato pulp, dirt, and chalk.
Chop and core the rest of the cabbage. Saute half an onion (chopped) in a large pan until it's sweet, then add the cabbage. Add some thyme or celery seeds if you like. Cook, tossing and stirring, until the cabbage is redder and softer, but not until it is limp.
Add 1/2 cup of cider vinegar to the hot pan, slap a cover on that baby, and remove from the heat. The vinegar steam will finish cooking the cabbage and the whole thing will come out unbelievably sweet.