After preparing and washing the cabbage, shred up very fine, chop up the onion, set these two in a saucepan over the fire with 1 quart of water, the butter and seasoning, and let all cook gently for 1 hour, or longer it the vegetables are not quite tender.
Add the milk and thickening when the vegetables are thoroughly tender, and let all simmer gently for 10 minutes; serve with little squares of toasted or fried bread, or plain rusks.