Lemongrass is the stalk of a plant that's full of citrusy aroma and flavor -- it actually has the same essential oils as lemons. Grown and used throughout Southeast Asia, it is most famous as a common ingredient in Thai food.
Store fresh lemongrass, wrapped loosely in a damp paper towel in an open plastic bag, in your fridge for several weeks. You can also freeze the whole stalks (they should be good for months), or go ahead and chop it up finely, and freeze in portions to use later.
Take your curries to the next level with fresh lemongrass. Make an unforgettable Tom Kha Gai soup. Or simply make a lovely lemongrass tea or cocktail. To use lemongrass, cut off the root end of the stalk, and remove any tough outer leaves. The pale center portion is what's used in most dishes. (But you can save the greener tops of the stalk for teas and drinks.) You have two options for using the center portion. For one, using a very sharp knife, you can thinly slice or mince this portion and then process into a pulp in a food processor -- or pound into a curry paste in a mortar and pestle, along with garlic, ginger, chilies, etc. The easier option is to cut the stalk into 3 inch lengths and then bruise these sections by bending them back and forth (to release their aroma). These bruised lengths can then be added to soups or curries. Before serving, remove these pieces, since they'll be too tough to eat. Since lemongrass is so fibrous, it can be a little extra work to prepare, but its incredible flavor is worth it.
Tom Kha Gai Soup (Thai Chicken Coconut Soup)
Eggplant Lemongrass Curry from the farmers at Transplanting Traditions
Lemongrass Turmeric Curry Paste (make a big batch and freeze it in portions to use later)