Nigella seeds are used widely in India, the Middle East, and North Africa to add a uniquely difficult to pinpoint flavor. It's at once peppery, oniony, herbal like oregano, and even nutty. They're great for topping naan, in salads, in korma, and to flavor preserved lemons. Use nigella in curries, stir-fry, pilaf, pickles, and maybe as a bagel topping.