Place salmon fillets, skin side down, in oiled baking dish large enough to accommodate fillets in a single layer with space in between to allow for even baking. Rub with a little oil and season with salt and pepper, if using. Roast salmon until almost cooked through, about 10 to 15 minutes, depending on thickness of salmon fillet. To test, a paring knife should slide through easily. Flesh should be a little rare in the centre as it will continue to cook when resting. Remove from oven and set aside.
