[iDon]

Not OP, but I found various info about the values of Nigella as a herbal remedy, e.g. with garlic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4687760/

When I read "black seed" in the comment I guessed it might be Nigella seeds, which are sprinkled atop pides in the local middle-eastern bakeries, adding a lovely piquancy to the bread.