Meanwhile, in a small skillet, toast the cumin and coriander seeds over moderate heat until fragrant, about 40 seconds; let cool. Transfer the seeds to a spice grinder and grind to a powder. Transfer the powder to a small bowl. Stir in the lemon juice, oil, garlic, ginger and the remaining 1 tablespoon of honey; season with salt and pepper. Pour the dressing over the potatoes and serve.