3 traditional baked fish Recipes

olive oil, plus extra, olive oil , for oiling, onions, finely chopped, carrots, thinly sliced, celery ribs, thinly sliced, dry white wine, tomatoes with juice, sugar, lemon, thinly sliced, chopped fresh flat-leaf parsley, chopped fresh marjoram, sea bass or 1 (2 -2 1/2 lb) tilapia fillets or 1 (2 -2 1/2 lb) red snapper, fat whole fish cleaned and scaled, salt and pepper

self rising flour, water, baking potatoes, oil, for frying, cod fish fillets, cut into 4 pieces, salt and pepper, as needed, lemon wedge, as needed