These preserved greens are not pickled, just dried with a whole lot of salt. They need to be rinsed well before use. Some of my older cookbooks mention them packaged in two forms, flat leaves or leaves rolled into a ball, both in plastic bags. I haven't seen the ball form around here, it may have gone out of style, a relic of the days before plastic bags. In any case, if the recipe calls for "a ball of chung choy", those balls weighed about 1½ ounces each.