Nigella or Kalonji as it's known in Hindi is a popular spice that is used on top of Naan, in Dal recipes and curries. It is also known as black seed, and incorrectly as black cumin, onion seed and black caraway. It is used as part of the spice mixture paanch phoran. Also quite popular in Turkey and Bosnia to flavor pastries and atop buns. The oil from the seed is used as herbal remedies to treat certain skin conditions.