Lightly acidify the fish fillets with lemon juice, season with salt and set aside.
Heat a few tablespoons of olive oil in a saucepan, sauté the vegetables, add vinegar and season with chili powder, pepper, salt and the bay leaves. As soon as the vegetables are cooked, remove the pan from the heat.
Heat olive oil in a pan and fry the fish fillets until golden brown and crispy. Then place in a flat, wide dish and pour the hot vegetable mixture over it.
Either serve hot with boiled potatoes or leave to marinate in the refrigerator for 1 day and then reheat.