Nigella seeds are a spice harvested from the plant Nigella sativa which was probably first grown in the Fertile Crescent and is now widely grown in India and Egypt. They are often mistakenly called onion seeds because they have a slight onion-like smell. They aren’t in any way related to onions, so the two seeds should not be confused. Furthermore, don’t plan nigella seeds and expect to get onions.

These black seeds are approximately 0.125 inches (about 3.18mm) in length and have a slightly triangular shape, and may also be confused with black sesame seeds. They form the basis for several Indian dishes, particularly in Northern regions, and are popular as sprinkled on naan, which is Indian flatbread, or in rice pilau. A five spice mix common in Bengal called paanch phoron may include nigella seeds as one of the five spices, mixing them with fennel, cumin, fenugreek and mustard seeds. Paunch phoron may be used to flavor fish or vegetables, particularly vegetables like eggplant. In fact, many cooks suggest that eggplant and nigella seeds are the best possible pairing of the vegetable and the spice.

There are many opinions on what nigella seeds taste like. Most agree they have little flavor when they are not cooked, but may impart a little bit of heat to dishes. When cooked, the seeds have been described as peppery and smoky, or descriptions compare the seeds to oregano. Perhaps the most amorphous adjective to describe nigella seeds is aromatic; many things have aromas, so this description makes it difficult to determine what aromatic may mean in this sense. Most agree the taste is light and occasionally slightly bitter.

You may find nigella seeds marketed as kalonji. Because of their high oil content and possible medicinal value, you’ll find numerous kalonji mixtures and preparations on the market. In Indian and Persian medicine, kalonji has been used as a cure to all ills. Some suggest the seeds take the sting out of scorpion bites, help treat intestinal problems, end facial paralysis, stop rheumatoid arthritis in its tracks, and treat kidney problems, heart ailments, and hemorrhoids. Though the seeds cannot possibly be the silver bullet cure for everything, they are high in antioxidants, and their smell is said to repel some insects. You may find kalonji in naturally made or organic insect repellents.

Though the seeds grow well, even when ignored, there are no large-scale efforts to grow them in the US. You can grow your own, but remember to get nigella sativa, and not other varieties of nigella — there are about 14 nigella varieties. Once the plants have developed seed pods after flowering, you can hang them upside down for several days to dry them, or shake the seeds loose and dry them in the sun for a few days. You should make some effort to cover them, as any outdoor creatures may be fond of the seeds and can easily deplete your supply.

You’ll also be able to find nigella seeds in many specialty foods markets, Asian grocery stores, or natural foods stores. Numerous Internet food suppliers stock them. If you’re having trouble locating them, try contacting a local Indian restaurant and ask them where they obtain their supply.