Heat a grill over medium high heat. Remove the steak from the marinade and generously season with salt and pepper. Place the steak on the grill and grill for 4-6 minutes on each side, turning 90 degrees halfway through to get crisscross grill marks. Cook until medium/medium rare, or medium, depending on your preference, and then remove to a cutting board and let rest for 10 minutes. Slice the flank steak against the grain and use for the salad.