According to my favorite Indian cookbook author, Madhur Jaffrey, black cumin seeds (nigella) are sold as kalonji in Indian and Pakistani markets, and as siyah danch in Middle Eastern markets. (health.com)
Hi Aimee, they're nigella seeds (sometimes also labelled as kalonji seeds)! (landsandflavors.com)
Add kalonji and salt, and rub in the ghee, oil or melted butter. (purevege.com)