Nigella seeds are one of those nebulous spices. If you bite into these little tear-shaped, matte, coal-black seeds raw, you get a little bitterness but otherwise very little flavor. When cooked, though, there develops a smokiness of sorts, a peppery, almost oregano-like flavor that is absolutely delicious. I love these in baked goods like in a biscuit or in my quickbread from a few months back.
Nigella seeds are found throughout Middle Eastern, South Asian, and even some African cooking. In Ethiopia, the seed may be crushed up in stews or may even be added to their spiced clarified butter. The quatre épices or Chinese five spice equivalent in South Asia is called paanch phoron, and it includes nigella along with fenugreek, cumin, fennel, and black mustard seeds. The seeds are also baked into Middle Eastern and South Asian flatbreads and added to pickles and chutneys.