Finished product should not resemble leather.
Combine all the ingredients except the flank steak in a glass or ceramic dish.
Place the flank steak in the dish and flip it to coat both sides of the meat with the marinade.
Cover with plastic wrap and refrigerate for at least 3 to 6 hours.
Heat a grill or grill pan over high heat.
Grill the steak for 2 minutes on each side, rotating the meat 90 degrees once on each side to achieve nice grill marks.
Remove the meat to a cutting board and let it rest for a few minutes before slicing.
Cut the meat against the grain into strips and serve with potatoes or pasta.