02Holding very sharp paring knife at 30-degree angle from fillets, cut 2 diagonal slits through skin and partially into flesh, making slits 1/2 inch apart.
03In large heavy skillet over high heat, heat 1/3 cup canola oil until hot but not smoking. Working in 3 batches, sprinkle fillets with 1 tablespoon salt and 1 teaspoon pepper and place skin-side down in hot pan. Saué until skin is rich golden brown, about 3 minutes, lowering heat if necessary to prevent burning. Turn fillets over and cook 3 minutes more. Transfer to platter and loosely cover with foil to keep warm. Cook remaining two batches in same manner, wiping pan clean between batches and starting with fresh oil for each batch.
04After removing last batch of fish, pour lemon juice into pan and swirl around to combine with pan juices. Drizzle over fish, then sprinkle with remaining 1/2 cup parsley. Garnish with tomato-olive mixture.