Put steak on a wire rack set on a rimmed baking sheet. Pat dry with paper towels. Season with 1/2 teaspoon salt per side. Chill uncovered for up to 3 hours. 
Remove steak from refrigerator 1 hour before grilling and let come to room temperature. Pat dry with paper towels. Season again with 1/2 teaspoon each of salt and pepper per side, pressing down so pieces adhere.
Build a two-zone fire in a charcoal grill for direct (medium-high coals) and indirect (medium-low coals) heat. Alternatively, heat a gas grill to high. Just before cooking, turn one burner on low. 
Sear steak over direct heat, flipping once, until nicely charred, 3-4 minutes per side. If a flare-up occurs, use tongs to gently slide the steak away from flames.
Move steak to indirect heat and continue grilling, flipping once, for 3-4 minutes per side. Using tongs, lift steak and sear both edges for 1-2 minutes per side to render out some of the fat.
Grill steak until an instant-read thermometer registers 120°F for rare, steak will carry over to 125°F, or medium-rare.
Transfer steak to a carving board; let rest for 10 minutes. Slice across the grain, season with coarse sea salt, and serve.