Place salmon on a large baking sheet or pan lined with aluminum foil. Place salmon on the foil and drizzle with the garlic oil. Sprinkle with salt, pepper and rosemary. Place in a cold oven. Turn the oven on to 400 degrees F. Set your timer for 25 minutes and then the salmon will be done.
Using a spatula, transfer the salmon to a serving platter, leaving the skin stuck to the foil. (A neat trick for removing the skin!)