GAS GRILL:
1. Turn on all burners to high, close the lid, and heat the grill until very hot, about 15 minutes. Scrape the grill grate clean with a grill brush. Leave on all burners on high. Increase the grilling time on the first side to 3 to 4 minutes, and on the second side to 4 to 5 minutes.
CHARCOAL GRILL:
1. Light a large chimney starter filled with hardwood charcoal (about 6 quarts) and allow to burn until all the charcoal is covered with a layer of fine gray ash. Build a single-level fire by spreading the coals out evenly over the bottom of the grill. Set the cooking rack in place, cover the grill with the lid, and let the rack heat up, about 5 minutes. Use a wire brush to scrape clean the cooking rack. The grill is ready when the coals are medium-hot. (see hot to gauge heat level on page 568.)
2. Gently sprinkle each side of the salmon fillets with salt and pepper.
3. Lightly dip a small wad of paper towels in vegetable oil; holding the wad with tongs, wipe the grill rack. Place the fillets skin-side down on the grill. Grill uncovered until the skin shrinks, separates from the flesh, and turns black, 2 to 3 minutes Gently flip the fillets with a meta spatula. Grill, uncovered, until the fillets are opaque throughout, yet translucent at the very center, 3 to 4 minutes. Serve immediately.