A highly aromatic, lemon-flavored herb often used in Asian cooking. To use, trim the fibrous ends and slice what remains into 3- to 4-inch sections. Cut each section in half lengthwise, exposing the layers. Rinse pieces under cold water to remove any grit and slice the lemongrass thinly. In a pinch, substitute 1/2 teaspoon finely shredded lemon peel for 1 tablespoon lemongrass.