1. In a medium sized pan, heat the oil, then add Brussels. Stir constantly and watch for them to brown slightly.
2. As soon as they do, add the shallots, raisins, and walnuts. Cook until the shallots are soft.
3. Turn the heat way down and splash the umeboshi vinegar over the whole thing. Stir well, and serve warm.
Brussels can be more or less cooked depending on how you like them. We like them to be still bright green and nowhere close to mushy. If you want them softer, cook the Brussels longer before you add the shallots and other things.