Combine the pepper and herb seasoning ingredients together in a small bowl and mix well to form a coarse paste.
Spread the paste evenly over both sides of each flank steak.
Wrap the flank steaks individually with plastic wrap and refrigerate for 2 to 12 hours.
Build a charcoal and/or wood fire for direct grilling.
Grill the steaks directly over the coals (approximately 450 to 500F) for 5 minutes on each side, until an internal temperature of 135 to 145F is reached for medium-rare to medium doneness.
Let the meat rest under tented foil for 10 to 15 minutes.
For optimum tenderness, cut the flank steaks across the grain into 1/4-inch-thick slices and serve.