Meanwhile, heat oil in a small skillet over medium-high heat; add mustard seeds. When the seeds begin to pop, cover the pan until the popping stops. Reduce heat to medium; add cashews and cook, stirring until golden brown, 30 seconds to 1 minute. Remove from heat and add lime juice, cilantro, chilies (or jalapeno), turmeric and salt. Add the mixture to the cooked rice; mix well.