f you haven't worked with lemongrass before, you need to know how to prepare it. Don't worry, it is easy, but do it carefully or you can end up with unpleasant woody bits in your stir-fry. Here's what you do: remove the outer layer of each stem and trim away the bottom 1/4" inch and most of the top, leaving only about a 3" piece that should be tender enough to sink a fingernail into. Now pound it with something heavy to release the flavors. Many cooks use the back edge of their knife, but you'll have to decide if you feel safe doing that. If not, a can of beans should work fine. Once you've given it a good thrashing, finely mince it and you are all set.