Baked salmon is a healthy entree that's simple to cook and versatile enough that you can find plenty of recipes to prepare without ever tiring of this fish. When cooking salmon, the size factor most directly affecting cooking times is its thickness; the thicker the cut, the longer it takes to cook through. If you have a large cut, it's probably a filleted side of salmon, typically sold in slabs weighing 1 pound or more. Season and bake this hefty piece as you would smaller fillets, and then it's easy to cut into individual servings once it's cooked.
Put an oven rack on the middle tier. Turn the oven on to 250 degrees Fahrenheit about 15 to 20 minutes before cooking to preheat. Slowly baking salmon at a low temperature is an effective way to melt the fat in a large cut, yielding a moist and succulent piece of fish.
Cover a baking tray with foil and rub some cooking oil over it to prevent sticking. Place the salmon on the tray, skin-side down.
Season the salmon to taste. For a fresh-tasting topping that helps keep the fish moist during cooking, finely chop some fresh herbs -- basil, dill, rosemary, sage, tarragon and thyme are all good picks -- and mix them with a little cooking oil, minced garlic and lemon zest. Spread this herb paste evenly over the top of the salmon. Or, for a spicier preparation, cover the salmon with blackening spices; for a dish inspired by Asian cuisine, glaze the salmon with teriyaki sauce or pour on some soy sauce and add on minced garlic and ginger. The possibilities are practically endless for salmon.
Put the salmon into the oven on the middle tier. Bake the fish for approximately 18 to 25 minutes, regardless of weight. Thinner cuts around 3/4-inch thick typically need around 18 minutes; cuts around 1 inch thick usually need about 20 to 22 minutes; and thicker cuts of 1 1/2 to 2 inches at their thickest point need 25 minutes or sometimes a little longer. Bake salmon until its flesh is opaque through to the center and its meat flakes apart easily. For certainty, confirm the salmon is cooked to 145 F at center with an instant-read food thermometer.