I've been working with a bunch of Thai recipes that call for the root of cilantro/coriander. In the summer, I found some bunches with the roots attached, but lately all of the cilantro I can find is cut higher up, so I only have stem. Stem is apparently the best substitute, but I keep wondering if there is a good source for the root, maybe frozen? Has anyone seem it around, maybe at an Asian market? Thanks in advance.