Remove the crowns from the broccoli, and refrigerate for later use. Remove the hard base of the stalk, about 1/2 inch, with a knife and discard. Peel the tough skin from the lower part of the stem and discard. Slice the stalk in very thin pieces, and place in a bowl or jar. Mix the ume plum vinegar and water together, and pour over the slices. Allow to marinate for 2 hours. Rinse to remove excess sodium before eating.
These pickles will keep for several days in the refrigerator. Leave pickles in pickling liquid until ready to eat. Remove several pieces at a time and rinse before eating. They become a little saltier the longer you store them. If too salty, soak the pickles for 10 minutes, and serve.
Per serving - 2 calories, 0 g fat (9% calories from fat), 0 g protein, 0 g carbohydrate, 0 g fiber, 0 mg cholesterol, 422 mg sodium