Since flank steak is so thin, it soaks up any seasoning or marinade well and cooks quickly. Keep it simple with olive oil, salt, and pepper, or use your favorite marinade.
Prep and preheat
Oil the flank steak and season with salt and pepper. Preheat the grill to 400°F (medium-high).
Sear and rotate
Sear for 1-2 minutes, then rotate. Cook another 2-3 minutes, then rotate again. Cook another 2-3 minutes, then flip.
Finish to temp
Cook until internal temperature reaches 135°F, about 5 minutes more.
Rest and serve
Remove from the grill, let rest for 10 minutes, slice across the grain, and enjoy.