(I put these seeds in the shell for the picture but they have nothing to do with the ocean)Nigella seeds are a spice used in many Indian dishes. It is from the plant Nigella sativa.
They look like black sesame seeds. I have had them sprinkled on naan bread but thought they were black sesame seeds.
I cook with them when making stir frys and I even put them in my eggs. They have a peppery, aromatic flavor with a slight bitter aftertaste.
The seed's oil has almost a cult following in eastern cultures using it for everything from stings, bites, intestinal issues, arthritis, kidney, and a slew of other ailments.
You can find this spice in many specialty stores or a spice market. I buy mine in the spice markets of NYC.