Marinade -- 24 - 48 hours.
Then surprisingly, cook it fast and medium rare is as far as you wanna go. Two minutes per side above hot coals or beneath a broiler.
Then, for this cut, a 5 minute rest covered in foil is particularly useful.
Now cut into strips.
I love this cut done in Italian dressing and the strips served with antipasto goodies.
And I love it for fajitas over a sour cream dessed chopped salad and topped with guac.