How to Make It
In a dry skillet, combine the mustard, cumin and coriander seeds and toast over moderate heat, stirring, until fragrant, about 3 minutes. Coarsely grind the seeds in a spice grinder or mortar.
In a bowl, combine all but 1 tablespoon of the kiwi with the yogurt, sour cream and onion. Stir in the spices, cilantro and chile powder and season with salt. Cover and refrigerate until cold. Garnish with the reserved kiwi and serve.