Curry leaves are an herb native to South Asia, unrelated to the ground spice mix called curry powder. They're an essential component of South Indian cooking, adding a subtle aroma to simple dishes and complexity to highly spiced ones, Rasam explains on Chowhound. Once cooked, curry leaves are edible, though most people simply push them aside on the plate.
Curry leaves are often available fresh at Indian markets, and freeze well—no need to defrost before cooking with them. Avoid dried curry leaves, which have no flavor or aroma. You can grow your own, either outdoors or in a large pot near a sunny window. Just be sure you're planting a curry leaf plant (Murraya koenigii) and not the unrelated curry plant (Helichrysum italicum).
One curry leaf–scented dish drawing raves from 'hounds is a New York Times recipe for coriander-cumin chicken, inspired by the Passover cooking of Sephardic Jews in Cochin, in the South Indian state of Kerala. It's fragrant, complex, and unusual, but easy to make, Nyleve says. To make it more authentically Keralan, Chowshok suggests using coconut oil in place of vegetable oil and sautéing the curry leaves with the onions instead of adding them to the sauce later. Use the leftover sauce for poaching fish or simmering vegetables.
And check out other ways Chowhounds use curry leaves.