Clean the flank or skirt steak up a little, cutting away some of the membranes and fat.
Make a paste of the remaining ingredients and rub the the meat on both sides with this paste. I cut the steak in half so I have two smaller ones and lay them on top of each other, but that's just me, I'm weird that way. Refrigerate overnight in a large, sealed zip lock bag.
Bring steak to room temperature by removing from fridge 30 minutes before cooking time. If you're grilling it over charcoal (and you should), get it insanely hot and put the steak close to the charcoal for about 2-3 minutes per side to sear it closed. Then move it further away and grill it for a total of about 15 minutes, turning it at least once. When it looks slightly charred and no longer feels bouncy when you poke it, it's probably done.
SLICE THINLY ACROSS THE GRAIN. Flank steak is a rather tough cut of meat and slicing it this way is very important for "cheery chewing". Serve the meat however you like, but they're quite good in a pita with a bit of lettuce, tomato and maybe a garlic sauce -- sort of like a home-made Shoarma.