Kalonji, also known as onion seeds or Nigella seeds, are small, black seeds that are commonly used in Indian and Middle Eastern cuisine. The seeds have a slightly bitter, peppery flavor and a strong, pungent aroma.

Kalonji is often used as a spice in cooking, particularly in savory dishes such as curries, stews, and vegetable dishes. It can also be used to flavor bread, such as naan or other types of flatbread. Additionally, Kalonji is sometimes used in pickling recipes or added to salad dressings.

Overall, Kalonji is a versatile spice that adds a unique flavor and aroma to many types of dishes. It is also believed to offer a range of fitness benefits, making it a popular ingredient in traditional medicine practices.