Place flank steak in resealable bag and add marinade. Squeeze as much air as possible out of the bag before pressing shut.
Store in fridge and let marinate at least 4 hours or overnight.
Preheat oven 425 deg F (220C).
Place flank steak on baking sheet and discard marinade.
Roast steak for 10 minutes. (See notes below for cooking times and doneness.)
Remove from oven and tent with foil. Let meat rest for 10 minutes.
Slice steak cross-grain at an angle.
Serve with salad, in a soft tortilla, or in a lettuce wrap.
Cook the steak by grilling, broiling, roasting, or pan-frying.
Flank steak cooks quickly; do not cook beyond medium doneness or it will end up tough.
Flank steak that is about ½" thick will come out at medium doneness in the stated temperature and time. If your steak is thicker, then it will be more of a medium-rare in the same amount of cooking time. Adjust the cooking time as necessary to suit your desired doneness of the meat.
Use an instant-read thermometer to determine the doneness. For medium-rare, thermometer should read about 125-130 deg F (51-54C). Medium is about 130-135 deg F (54-57C).
Slicing the meet across the grain at an angle (about 45 degrees) and thinly makes the slices of steak easier to bite and chew.
Serve with a side of mustard and sea salt for dipping, if desired.
This steak goes great with a Caesar salad or in a wrap.