Charcoal-Grilled Chilean Sea Bass Fillets

Ignite about 6 quarts (1 large chimney, or about 6 pounds) charcoal briquettes and burn until covered with thin coating of light gray ash, 20 to 30 minutes. Spread coals over one half of grill bottom to create 2-level fire. Position grill rack over coals, cover grill with lid, and heat rack until hot, about 5 minutes. Scrape hot grill rack clean with wire brush.

Sprinkle fish generously with salt and pepper; spray both sides lightly with cooking spray. Dip small wad of paper towels in vegetable oil; holding wad with tongs, wipe grill rack.

Place fish directly over coals and grill until golden brown on first side, 4 to 5 minutes. Flip fish onto second side and continue to grill until golden brown on second side, 4 to 5 minutes longer. Move fish to cool part of grill and continue cooking until center of fillets is opaque and cooked through, 3 to 6 minutes longer. Serve immediately, with lemon or lime wedges if desired.