Radishes with Sour Cream Dressing and Nigella Seeds

In a small skillet, toast the nigella and mustard seeds over moderate heat until fragrant, about 1 minute. Transfer the seeds to a plate to cool completely.

In a small bowl, combine the sour cream with the vinegar and cumin and season with salt and pepper.

Arrange the radishes on a large plate or platter. Drizzle with the dressing. Garnish with the toasted seeds and serve.