Rub fish fillets with garlic and place them on a glass bowl. Cover fish fillets with olive oil. Place onion on the fillets. Cover and refrigerate overnight.
Remove fish from the refrigerator and transfer fillets with the garlic, onion and olive oil to a
ovenproof serving dish. Sprinkle with salt and pepper.
Bake in preheated oven at 350ºF (180ºC) until fish is tender. Remove from the oven and serve with a salad or a purée.
How to fillet, skin and debone fish