The flank steak comes from the abdominal or flank area of an animal. In this case, we are using beef flank steaks. These are the same steaks that are used for fajitas, so I thought that would be a good thing to make with this marinated beef flank steak.
I marinated this flank steak overnight. It needs about 12–18 hours to soak in the flavors from the marinade, so leave enough time. If you decide to skip the marinade, season the steak per your preference. But you should probably tenderize it with something, either a hammer or a jaccard. A jaccard is a tool with a bunch of blades on it that penetrate the meat and cut up up inside just enough to tenderize it a bit. Depending on how many wacks you give it.
1. Pick up a beef flank steak. They are usually a fairly uniform shape, but they can vary in size depending on the size of the beef cow. Some flank steaks come with the fat still attached, and it's up to you whether to remove it or not while you cook. It may help keep the meat juicy. If you marinate the meat, it's going to be extra juicy anyway, and the fat cap will just get in the way. Either way, I would definitely remove it before you serve the meat.
2. Season, marinate, or tenderize the flank steak. The flank steak can be a pretty tough cut of meat, which is why we cut it across the grain. It still benefits from being marinated or tenderized. To tenderize the meat, give it a few whacks with a meat mallet or jaccard. Don't overdo it! You want the meat to keep its general shape and thickness. Turn the broiler on high and move an oven rack to the second rung under it. Let the broiler heat up for a few minutes before you put the flank steak under it.
3. Broil the flank steak. Lay the meat on the broiling pan so that it will be directly under the heat and positioned to get an even distribution. After 3–4 minutes, flip the flank steak over and broil the other side. After another 3 minutes, check the internal temperature with a digital thermometer. Cook the steak to: 120–125 degrees F for rare, 130–140 for medium rare, 140–150 for medium, 150–160 for medium well, and 160+ for well done. Of course, anything past medium may end up being chewy.
4. Let the broiled flank steak rest. Once the flank steak is to the desired temperature, which shouldn't take long since it is so thin, let it rest for 8–10 minutes. There may be some juices coming out, so put it on something to collect them. After the flank steak has rested, use a very sharp knife to cut it thinly across the grain. This will help make the meat less chewy. If you want happier dinner guests, the thinner you cut it the better.
Buy a flank steak that looks and smells fresh. Sometimes they get a little grey from normal oxidation, but smell it to make sure it's not going bad.
The marinade should be allowed to soak for at least 12 hours in order to be effective.
If you go with the tenderizer, only give it a few whacks to break up some of the internal striations. You don't really want to flatten it, unless you are making a roulade.
Some electric broilers may be a little under-powered, so don't push it too much when trying to brown the flank steak or you may end up overcooking the inside. Keep checking the temperature with a thermometer, and take it out of the broiler when it's done.
Remember to cut it thinly across the grain.