Have ingredients measured and nearby before beginning. Heat oil in a small skillet over high heat. Add mustard seeds. (They will begin popping immediately so have a cover close at hand for escaping seeds.) Cook until popping stops.
Lower heat, add cumin seeds, and cook until they turn golden, about 1 minute. Stir in garlic for 10 seconds, then ginger for 10 seconds more, and remove from heat. Stir in turmeric, paprika, pepper flakes, and salt. Mix spices and yogurt in a bowl. Chill before serving.
c.1997, M.S. Milliken & S. Feniger, all rights reserved