1. Clean and cut red cabbage into quarters (discard core) and then coarsely shred (or use food processor).
2. Add onion and cabbage in a large pot with butter and/or olive oil. Cook slowly to reduce.
3. Mix rest of ingredients (including the rest of butter) together into bowl, pour into pot. Mix well.
4. Simmer slowly for 30-45 minutes. Check to make sure that the juices have not 100% evaporated--you do not want anything to burn on the bottom. You can add 1-2 tablespoons of apple cider vinegar if needed. Stir occasionally.
5. Simmer till tender. Season to taste. (Add sugar, salt, pepper, etc. to your liking. Some people like more sugar, some more salt. I noticed by adding a little bit of vinegar and salt on one batch, it helped a lot. But, you can't really do a true taste test till the next day. After you reheat it, taste again and see what you think it needs for a balance of sweet, sour, and salty. Cabbage just happens to need more salt than people realize for flavor. We are conservative on salt in this recipe.)
6. Best if refrigerated over-night and reheated the next day!