Coriander is a seed of the same plant that gives us cilantro. Its origin is ancient enough that it's mentioned in the Bible. It's essential to many Latin American and Indian dishes but its full reach is global. It's a subtle spice, with hints of both lemon and a more earthy, nutty taste. It helps round out the flavor profile of a profusion of dishes, from curries to homemade pickles; it's compatible with both sweet and savory dishes. Coriander pairs particularly well with cumin, lemon, lime and orange, pepper, cinnamon and chili peppers.
Maximize the flavor of whole seeds by dry-toasting them briefly in a small skillet over medium-low heat; you'll be able to smell them when they're done. Sprinkle whole toasted coriander seeds over roast or pan-fried potatoes, use them to season chicken soup or broth, or add to long-simmered stews and braises.
You can also dry-toast the seeds and then grind them; a fresh grind will have more flavor than preground coriander, which loses its citrus notes quickly. Try adding ground coriander to a carrot soup for a flavor boost. Use ground coriander as a component in a dry rub for pork, chicken or beef or add it to yogurt for an easy sauce. A pinch or two enhances lentil dishes as well.