Nigella seeds are a spice harvested from the plant Nigella sativa, which probably first grew in the Fertile Crescent and now grows throughout India and Egypt. While they can smell a bit like onions, they typically have a mild somewhat "peppery" flavor, which intensifies when cooked. They can be used in a wide range of dishes, though they are most popular in Indian cuisine. Some people use oil from nigella seeds as an antioxidant and for upset stomach.
Common Culinary Uses
Indian chefs use nigella seeds to form the basis for several dishes, particularly in Northern regions, and often sprinkle them on naan or Indian flatbread and include them in rice pilau. A five spice mix common in Bengal called paanch phoron may include these seeds as one of the five spices; mixing them with fennel, cumin, fenugreek and mustard seeds. Indian chefs often use paanch phoron to flavor fish or vegetables, particularly eggplant. In fact, many cooks suggest that eggplant and nigella seeds are among the best possible pairings of a vegetable and spice.
Taste and Aroma
There are many opinions on what nigella seeds taste like, though most people agree they have little flavor when they are not cooked, but may impart a little bit of heat to dishes. When cooked, many people describe the seeds as peppery and smoky, or compare them to oregano. Most tasters agree the flavor is light and occasionally slightly bitter. Cooking them also makes them more aromatic, releasing their scent into the kitchen and the dish itself.
Appearance and Other Names
These black seeds are approximately 0.125 inches (about 3.18mm) in length and have a slightly triangular shape, so people often confuse them with black sesame seeds. Some people also mistakenly call them "onion seeds" because they have a slight onion-like smell. They are not in any way related to onions, however, so the two plants should not be confused.
Buying and Cultivating the Seeds
Many specialty food markets, Asian grocery stores, and natural foods stores stock nigella seeds. Nigella sativa is also quite easy to grow, allowing people to cultivate them for cooking. Cooks can gather and dry seed pods, or shake the seeds loose and then dry them separately.
Medicinal Uses
Some stores market nigella seeds as kalonji. Because of their high oil content and possible medicinal value, companies make numerous kalonji mixtures and preparations. In Indian and Persian medicine, the seeds have been used to help treat intestinal problems, stop rheumatoid arthritis, and treat kidney problems. They are high in antioxidants, and their smell is said to repel some insects. Further research may still be necessary, however, so people should consult a healthcare professional before altering or starting any medical treatment.