Firm, white-fleshed fish work well here, but sardine and mackerel fillets are also quite good. Please read About Deep-Frying and Shallow-Frying Fish.
Combine in a small saucepan:
Bring to a boil over high heat, then remove from the heat. Thoroughly whisk together on a plate:
Dredge in the flour mixture to coat well:
Heat in a large skillet over medium-high heat until hot but not smoking:
Fry the fillets until golden brown and opaque at the center, 3 to 4 minutes on each side depending on the thickness. Transfer to a wide shallow bowl. Pour the vinegar mixture on top and sprinkle with:
Let sit until the fish has cooled completely to allow the marinade to flavor the fish. Serve at room temperature.