Toss the fish with the ginger, coriander, salt and lemongrass powder. Heat enough oil for deep frying.
Toss the seasoned fish with the rice flour. Dust off the excess and place in the hot oil. Fry for 3-4 minutes, until golden brown. Drain on paper towels.
To make the dressing, combine all ingredients except the oil. Mix well. Slowly drizzle in the olive oil, whisking constantly.
To make the salad, combine all salad ingredients with the fish. Add 6 tablespoons of the papaya dressing and toss well.