Remove any bones from the cod loins. Place them in a roasting dish and add the oil until they are half covered. Flavour the oil with 2 bay leaves and 4 garlic cloves lightly crushed. Cook in the oven at 160°C for 30 mins. or until the cod starts to flake apart.
Cut the red onions into wedges and sauté on a high heat with a little oil, salt and sugar. Do not overcook as the onion must remain crunchy. Add and reduce the vinegar.
Break the cornbread into crumbs. Fry gently in oil with a crushed clove of garlic until they become crispy. Season with salt.
Place the cornbread in the centre of the plate and top with the cod loin and red onion. Use a whisk to emulsify the oil left in the roasting dish and pour over the cod. Serve with a watercress salad.