Add onions to TM bowl, chop 7 sec/ speed 4; Add EVOO, white pepper, salt, cook 10 minutes/100C/speed 3; Add white vinegar, capers & bay leaves, cook 5 min/100C/ REV/ Speed 2 Transfer to dish and let cool down.
Season fillets with salt and pepper; Coat fillets in flour on both sides, Heat oil in frying pan; Fry fillets for about 1 minute on each side. Remove and drain on paper towels
To Assemble: Spoon half of the cooled onion relish into a shallow dish, place fillets on top. Top with more onion relish, cover and let marinate for several hours or overnight.