flour with salt and pepper. Cut the fish fillets on the diagonal into
serving pieces, then coat in the seasoned flour.
Heat the oil
and butter together in a large nonstick frying pan until foaming. Add as
many pieces of fish as the pan will hold and fry over a medium heat for
1-2 minutes on each side until crispy and golden. Remove the fish pieces
with a slotted spoon and set aside on a plate. Repeat with any remaining
pieces of fish, if necessary.
Add the white
wine, vinegar, sugar and raisins to the pan with salt and pepper to taste
and stir over a moderate to high heat until reduced. Return the fish to
the pan, then shake the pan and spoon the sauce over the fish until the
pieces are evenly coated. Serve immediately.