Preheat your grill to medium-high heat (around 375-400°F).
Once the grill is hot, place the flap meat directly onto the grill grates. Grill for about 4-5 minutes per side for medium-rare. Flap meat is best served medium-rare to medium to ensure it stays tender and juicy.
Once cooked to your liking, remove the flap meat from the grill and let it rest for 5-10 minutes before slicing
After resting, slice the flap meat thinly against the grain.